* http://victorgrau.mit.edu/caterpike
* http://drewsminiblog.blogspot.ch/2010/09/making-cargo-bike.html
* [https://web.archive.org/web/20160409034414/http://www.wackosgarage.com/2014/01/bakfiets/ Paul Wackowski (très élégant)]
* John Muir's:
** http://www.francescycles.com/new-page/