TY - BOOK TI - Productive thinking "First edition." AU - Wertheimer, Max, 1880-1943. AU - Asch, Solomon E. (Solomon Elliott), 1907- ed. PB - Harper & brothers PP - New York ; London : Harper & brothers, [1945]. PY - 1945 UR - https://library.korea.ac.kr/detail/?cid=CAT000000101795&ctype=m