TY - BOOK ID - 126932857 TI - aha! : insight PY - 1997 SN - 9780716710172 071671017X PB - New York, N.Y.: Scientific American books, DB - UniCat KW - Puzzles KW - Mathematical recreations KW - Problem Solving KW - Creative thinking UR - https://www.unicat.be/uniCat?func=search&query=sysid:126932857 AB - ER -