Flashcard set to accompany the 1962 Holt, Rinehart and Winston, Inc. textbook:  Deutsch: Verstehen und Sprechen by Rehder, et.al It uses a unique system of punched holes and a knitting needle to pull out the exact images needed to support a particular unit.  The cards do not have to be kept in any particular order to quickly be able to access the images required.  German instructors or others interested in the history of language instruction would find this a fascinating addition to their collections.  I do not have a copy of the original text for sale, but they are still available from various sellers.   Flashcards are large-scale:  10" x 14" in sturdy laminated cloth case.