http://book.klll.cc/ebooks/author/6721.opds?sort_order=release_date 2025-11-18T13:19:28Z Books by Conant, Levi L. (Levi Leonard) Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-11-18T13:19:28Z https://en.wikipedia.org/wiki/Levi_L._Conant See also: en.wikipedia 2025-11-18T13:19:28Z https://book.klll.cc/ebooks/16449.opds The Number Concept: Its Origin and Development Levi L. Conant