1Edward Mecurdy. The Notebooks of Leonardo da Vinci.arranged and rendered into English. London: Jonathan Cape Ltd,30 Bedford Square, 1977, Vol Ⅰ. 1-41, 221.
2Martin Kemp. Leonardo da Vinci. Singapore: Tien Wah Press (PTE) Ltd for J.M.Dent & Sons Ltd in London, 1981.131, 132.
4Edward Mecurdy. The Notebooks of Leonardo da Vinci. arranged and rendered into English. London:Jonathan Cape Ltd, 30 Bedford Square, 1977, Volume Ⅱ.67,46,46,46,10,46,46,58,33,44,58,66,26,26,105,9,87,252,9,46,26,46,131.
5Leonardo da Vinci. the Codex Leicester: Note Book of a Genius Bibliography. Sydney: Power-house Publishing,2000. 132.