Springer. 1988. ISBN 0-387-96426-6. ,在書中有關潘洛斯三角的章節中,作者將以上觀察到的性質歸功於JohnStillwell的成果 维基共享资源中相关的多媒体资源:潘洛斯三角 An article about impossible triangle sculpture
Market-Frankford Line, the Ridge Avenue spur line, and the PATCO High Speed Line. Stillwell, Eileen. Google Transit features PATCO schedule. Courier-Post. January
Press, Chicago, IL, 2000. ISBN 0-226-31719-6, ISBN 0-226-31721-8. Stillwell, John (2002), Mathematics and its history, Springer, p. 374, ISBN 978-0-387-95336-6