diff --git a/quantecon/__init__.py b/quantecon/__init__.py
index 96b26c808..5ad125f53 100644
--- a/quantecon/__init__.py
+++ b/quantecon/__init__.py
@@ -38,9 +38,11 @@
 from ._filter import hamilton_filter
 from ._lqnash import nnash
 from ._ivp import IVP
-from .lss import LinearStateSpace
-from .matrix_eqn import solve_discrete_lyapunov, solve_discrete_riccati
-from .quadsums import var_quadratic_sum, m_quadratic_sum
+from ._lss import LinearStateSpace
+from ._matrix_eqn import solve_discrete_lyapunov, solve_discrete_riccati
+from ._quadsums import var_quadratic_sum, m_quadratic_sum
+from ._rank_nullspace import rank_est, nullspace
+from ._robustlq import RBLQ
 #->Propose Delete From Top Level
 #Promote to keep current examples working
 from .markov import MarkovChain, random_markov_chain, random_stochastic_matrix, \
@@ -51,8 +53,7 @@
 #Imports that are deprecated and will be removed in further versions
 from . import (ecdf, arma, compute_fp, discrete_rv, dle, estspec, filter,
 			   graph_tools, gridtools, inequality, ivp, kalman, lae,
-			   lqcontrol, lqnash)
+			   lqcontrol, lqnash, lss, matrix_eqn, quadsums, rank_nullspace,
+			   robustlq)
 #<-
-from .rank_nullspace import rank_est, nullspace
-from .robustlq import RBLQ
 from .util import searchsorted, fetch_nb_dependencies, tic, tac, toc
diff --git a/quantecon/_dle.py b/quantecon/_dle.py
index 3f619dd3e..e7c480d4d 100644
--- a/quantecon/_dle.py
+++ b/quantecon/_dle.py
@@ -4,9 +4,9 @@
 """
 
 import numpy as np
-from .lqcontrol import LQ
-from .matrix_eqn import solve_discrete_lyapunov
-from .rank_nullspace import nullspace
+from ._lqcontrol import LQ
+from ._matrix_eqn import solve_discrete_lyapunov
+from ._rank_nullspace import nullspace
 
 class DLE(object):
     r"""
diff --git a/quantecon/_kalman.py b/quantecon/_kalman.py
index 0299fd9ab..886d8d5c9 100644
--- a/quantecon/_kalman.py
+++ b/quantecon/_kalman.py
@@ -10,8 +10,8 @@
 from textwrap import dedent
 import numpy as np
 from scipy.linalg import inv
-from quantecon.lss import LinearStateSpace
-from quantecon.matrix_eqn import solve_discrete_riccati
+from ._lss import LinearStateSpace
+from ._matrix_eqn import solve_discrete_riccati
 
 
 class Kalman:
diff --git a/quantecon/_lqcontrol.py b/quantecon/_lqcontrol.py
index a1f736c50..2688f8dbb 100644
--- a/quantecon/_lqcontrol.py
+++ b/quantecon/_lqcontrol.py
@@ -7,7 +7,7 @@
 from textwrap import dedent
 import numpy as np
 from scipy.linalg import solve
-from .matrix_eqn import solve_discrete_riccati, solve_discrete_riccati_system
+from ._matrix_eqn import solve_discrete_riccati, solve_discrete_riccati_system
 from .util import check_random_state
 from .markov import MarkovChain
 
diff --git a/quantecon/lqcontrol.py b/quantecon/lqcontrol.py
index 3e57e44ed..56466c066 100644
--- a/quantecon/lqcontrol.py
+++ b/quantecon/lqcontrol.py
@@ -20,7 +20,7 @@ def __getattr__(name):
                 f"'{name}'."
             )
 
-    warnings.warn(f"Please use `{name}` from the `quantecon` namespace, the"
+    warnings.warn(f"Please use `{name}` from the `quantecon` namespace, the "
                   "`quantecon.lqcontrol` namespace is deprecated. You can use"
                   f" the following instead:\n `from quantecon import {name}`.",
                   category=DeprecationWarning, stacklevel=2)
diff --git a/quantecon/tests/test_kalman.py b/quantecon/tests/test_kalman.py
index d717f03a6..df46f5516 100644
--- a/quantecon/tests/test_kalman.py
+++ b/quantecon/tests/test_kalman.py
@@ -4,8 +4,7 @@
 """
 import numpy as np
 from numpy.testing import assert_allclose
-from quantecon.lss import LinearStateSpace
-from quantecon import Kalman
+from quantecon import LinearStateSpace, Kalman
 
 
 class TestKalman:
diff --git a/quantecon/tests/test_lqnash.py b/quantecon/tests/test_lqnash.py
index 9f3dab637..da5899743 100644
--- a/quantecon/tests/test_lqnash.py
+++ b/quantecon/tests/test_lqnash.py
@@ -4,8 +4,7 @@
 """
 import numpy as np
 from numpy.testing import assert_allclose
-from quantecon import nnash
-from quantecon import LQ
+from quantecon import nnash, LQ
 
 
 class TestLQNash:
diff --git a/quantecon/tests/test_lss.py b/quantecon/tests/test_lss.py
index 7d4d2106f..ec6f1f327 100644
--- a/quantecon/tests/test_lss.py
+++ b/quantecon/tests/test_lss.py
@@ -4,7 +4,7 @@
 """
 import numpy as np
 from numpy.testing import assert_allclose, assert_, assert_raises
-from quantecon.lss import LinearStateSpace
+from quantecon import LinearStateSpace
 
 
 class TestLinearStateSpace:
diff --git a/quantecon/tests/test_lyapunov.py b/quantecon/tests/test_lyapunov.py
index 61e9cefa2..d22f9cba5 100644
--- a/quantecon/tests/test_lyapunov.py
+++ b/quantecon/tests/test_lyapunov.py
@@ -4,7 +4,7 @@
 """
 import numpy as np
 from numpy.testing import assert_allclose
-from quantecon.matrix_eqn import solve_discrete_lyapunov
+from quantecon import solve_discrete_lyapunov
 
 
 def test_dlyap_simple_ones():
diff --git a/quantecon/tests/test_matrix_eqn.py b/quantecon/tests/test_matrix_eqn.py
index e2bc911d8..bf1e94250 100644
--- a/quantecon/tests/test_matrix_eqn.py
+++ b/quantecon/tests/test_matrix_eqn.py
@@ -4,7 +4,7 @@
 """
 import numpy as np
 from numpy.testing import assert_allclose
-from quantecon import matrix_eqn as qme
+from quantecon import solve_discrete_lyapunov
 
 
 def test_solve_discrete_lyapunov_zero():
@@ -12,7 +12,7 @@ def test_solve_discrete_lyapunov_zero():
     A = np.eye(4) * .95
     B = np.zeros((4, 4))
 
-    X = qme.solve_discrete_lyapunov(A, B)
+    X = solve_discrete_lyapunov(A, B)
 
     assert_allclose(X, np.zeros((4, 4)))
 
@@ -22,7 +22,7 @@ def test_solve_discrete_lyapunov_B():
     A = np.ones((2, 2)) * .5
     B = np.array([[.5, -.5], [-.5, .5]])
 
-    X = qme.solve_discrete_lyapunov(A, B)
+    X = solve_discrete_lyapunov(A, B)
 
     assert_allclose(B, X)
 
@@ -32,8 +32,7 @@ def test_solve_discrete_lyapunov_complex():
                   [         1,          0]])
     B = np.eye(2)
 
-    X = qme.solve_discrete_lyapunov(A, B)
+    X = solve_discrete_lyapunov(A, B)
 
     assert_allclose(np.dot(np.dot(A, X), A.conj().transpose()) - X, -B,
                     atol=1e-15)
-
diff --git a/quantecon/tests/test_quadsum.py b/quantecon/tests/test_quadsum.py
index 24ff94d91..60011b6c6 100644
--- a/quantecon/tests/test_quadsum.py
+++ b/quantecon/tests/test_quadsum.py
@@ -4,7 +4,7 @@
 """
 import numpy as np
 from numpy.testing import assert_allclose
-from quantecon.quadsums import var_quadratic_sum, m_quadratic_sum
+from quantecon import var_quadratic_sum, m_quadratic_sum
 
 
 def test_var_simplesum():
diff --git a/quantecon/tests/test_rank_nullspace.py b/quantecon/tests/test_rank_nullspace.py
index 8518a7431..667c30966 100644
--- a/quantecon/tests/test_rank_nullspace.py
+++ b/quantecon/tests/test_rank_nullspace.py
@@ -4,7 +4,7 @@
 """
 import numpy as np
 from numpy.linalg import matrix_rank as np_rank
-from quantecon.rank_nullspace import rank_est, nullspace
+from quantecon import rank_est, nullspace
 
 
 class TestRankNullspace:
diff --git a/quantecon/tests/test_ricatti.py b/quantecon/tests/test_ricatti.py
index 6247be326..fff7139fc 100644
--- a/quantecon/tests/test_ricatti.py
+++ b/quantecon/tests/test_ricatti.py
@@ -4,7 +4,7 @@
 """
 import numpy as np
 from numpy.testing import assert_allclose, assert_raises
-from quantecon.matrix_eqn import solve_discrete_riccati
+from quantecon import solve_discrete_riccati
 import pytest
 
 
diff --git a/quantecon/tests/test_robustlq.py b/quantecon/tests/test_robustlq.py
index 7573c36c5..51c8b8539 100644
--- a/quantecon/tests/test_robustlq.py
+++ b/quantecon/tests/test_robustlq.py
@@ -4,8 +4,8 @@
 """
 import numpy as np
 from numpy.testing import assert_allclose, assert_
-from quantecon.lqcontrol import LQ
-from quantecon.robustlq import RBLQ
+from quantecon import LQ
+from quantecon import RBLQ
 
 
 class TestRBLQControl: