May 24, 2012
Finally, by the publication of the 1975 Westermann Schulatlas, the border adjustment with Poland is fully recognized, and the solid and dashed lines are reversed. 
It turns out that West Germany did not legally recognize the Oder–Neisse line with Poland until 1970.

Finally, by the publication of the 1975 Westermann Schulatlas, the border adjustment with Poland is fully recognized, and the solid and dashed lines are reversed. 

It turns out that West Germany did not legally recognize the Oder–Neisse line with Poland until 1970.