cleans empty ref section

01-spatial-data.qmd

@@ -1022,4 +1022,3 @@ For example, if the area output was in $m^2$ and we need the result in $km^2$, t
 
 <!-- ## Exercises -->
 
-## References

02-attribute-operations.qmd

@@ -579,4 +579,3 @@ plt.bar(*freq);
 
 <!-- ## Exercises -->
 
-## References

03-spatial-operations.qmd

@@ -1344,4 +1344,3 @@ An alternative worflow to `rasterio.merge.merge`, for calculating a mosaic as we
 
 -   Write a function which accepts and array and an `int` specifying the number of rows/columns to erase along an array edges. The function needs to return the modified array with `np.nan` values along its edges. -->
 
-## References

04-geometry-operations.qmd

@@ -1426,5 +1426,3 @@ rasterio.plot.show(rasterio.open('output/dem_resample_maximum.tif'), ax=ax);
 ```
 
 <!-- ## Exercises -->
-
-## References

05-raster-vector.qmd

@@ -1073,5 +1073,3 @@ gpd.GeoSeries(coastline).plot(ax=ax, edgecolor='black');
 ```
 
 <!-- ## Exercises -->
-
-## References

06-reproj.qmd

@@ -838,4 +838,3 @@ More information on CRS modifications can be found in the [Using PROJ](https://p
 
 <!-- ## Exercises -->
 
-## References

07-read-write.qmd

@@ -931,4 +931,3 @@ In such cases, the same considerations shown for `int` apply to `float` rasters
 
 <!-- ## Exercises -->
 
-## References

08-mapping.qmd

@@ -679,5 +679,3 @@ m.save('output/map.html')
 <!-- ## Mapping applications Streamlit? -->
 
 <!-- ## Exercises -->
-
-## References