I would like to know what are the most famous German secondary school textbooks for physics, electronics, or mathematics, during the post WW2 era. In other words, these are textbooks that were used in the Gymnasium, Realschule, or Hauptschule, from c. 1950-1990. Thank you. P.S. Although my question is about textbooks in Bundesrepublik Deutschland, it would also be good to know which ones were used in the DDR.