«Brief history of Humber». Humber Car Museum. Archivado desde el original el 2 de marzo de 2012. Consultado el 27 de enero de 2014. «Thomas thought that this could be improved upon, and in 1868 invented the firsty 'safety' bicycle ever produced».
«Bicycle History: Birmingham». Online Vintage Bicycle Museum. Consultado el 23 de julio de 2013. «A better idea of the "B.S.A." Safety can be seen ... 32-inch driving wheel ... 20-inch steer».
«Brief history of Humber». Humber Car Museum. Archivado desde el original el 2 de marzo de 2012. Consultado el 27 de enero de 2014. «Thomas thought that this could be improved upon, and in 1868 invented the firsty 'safety' bicycle ever produced».
Herlihy, David V. (2004). Bicycle: the History. Yale University Press. p. 225. ISBN0-300-10418-9. «...it not only prevailed as the universal bicycle style, it also triggered an unprecedented world-wide demand that culminated in the great boom.»
