TY - BOOK AU - Rachinskii,Sergei Aleksandrovich TI - 1001 задача для умственного счета AV - QA PY - 2005/// PB - Project Gutenberg KW - Word problems (Mathematics) KW - Mathematics -- Problems, exercises, etc N1 - Public domain in the USA; Electronic text UR - http://www.gutenberg.org/ebooks/16527 ER -