http://book.klll.cc/ebooks/subject/14672.opds 2025-09-20T12:03:47Z Books about Refraction, Double (sorted by popularity) Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-09-20T12:03:47Z https://book.klll.cc/ebooks/14725.opds Treatise on light : In which are explained the causes of that which occurs in reflexion, & in refraction and particularly in the strange refraction of Iceland crystal Christiaan Huygens