http://book.klll.cc/ebooks/author/36526.opds?sort_order=downloads 2025-11-16T21:30:50Z Books by Clarke, Hans Thacher Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-11-16T21:30:50Z https://en.wikipedia.org/wiki/Hans_Thacher_Clarke See also: en.wikipedia 2025-11-16T21:30:50Z https://book.klll.cc/ebooks/33663.opds The Origin and Development of the Quantum Theory Max Planck