00531cam a2200181 4500 405694088 TxAuBib 20181210120000.0 191210s2019||||||||||||||||||||||||eng|u 60893 Project Gutenberg PGUSA eng TxAuBib Brumbaugh, Martin G. Thinking and learning to think [Gutenberg] / Martin G. Brumbaugh. Project Gutenberg, 2019. Public domain in the USA. Text. http://www.gutenberg.org/ebooks/60893 TXTLL