Add 3PN for xorshift

THIRD-PARTY-NOTICES.TXT

@@ -289,6 +289,7 @@ https://github.com/ucb-bar/berkeley-softfloat-3
 https://github.com/ucb-bar/berkeley-softfloat-3/blob/master/COPYING.txt
 
 License for Berkeley SoftFloat Release 3e
+-----------------------------------------
 
 John R. Hauser
 2018 January 20
@@ -323,3 +324,20 @@ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+License notice for Xorshift RNGs
+--------------------------------
+
+George Marsaglia
+2003-07-04
+Journal of Statistical Software
+License: http://creativecommons.org/licenses/by/3.0/
+
+https://www.jstatsoft.org/article/view/v008i14
+https://www.jstatsoft.org/index.php/jss/article/view/v008i14/xorshift.pdf
+
+License notice for Xorshift (Wikipedia)
+---------------------------------------
+
+https://en.wikipedia.org/wiki/Xorshift
+License: https://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License