https://openlibrary.org/books/OL13446484M/Drawing_made_easy
https://openlibrary.org/books/OL7203499M/What_to_draw_and_how_to_draw_it
http://www.gutenberg.org/
http://www.gutenberg.org/files/486/486-h/486-h.htm
http://www.gutenberg.org/files/514/514-h/514-h.htm
http://www.gutenberg.org/files/2788/2788-h/2788-h.htm
http://www.gutenberg.org/files/2726/2726-h/2726-h.htm
http://digital.library.upenn.edu/books/
Here are some other resources that you can't find on the internet:
School Library
Local Public Library