http://book.klll.cc/ebooks/subject/3910.opds?sort_order=title 2025-08-09T09:22:56Z Books about Number concept (sorted alphabetically) Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-08-09T09:22:56Z https://book.klll.cc/ebooks/subject/3910.opds?sort_order=release_date Sort by Release Date 2025-08-09T09:22:56Z https://book.klll.cc/ebooks/subject/3910.opds?sort_order=downloads Sort by Popularity 2025-08-09T09:22:56Z https://book.klll.cc/ebooks/48312.opds Grundlagen der Arithmetik (German) Gottlob Frege 2025-08-09T09:22:56Z https://book.klll.cc/ebooks/16449.opds Number Concept: Its Origin and Development Levi L. Conant