How in the World?. Reader's Digest Association. 1990. s. 29. ISBN978-0-89577-353-1. «The world's first steel-edged cut-throat' razors were introduced in Sheffield in 1680.»
Melvyn Jones (30. september 2004). The Making of Sheffield. Wharncliffe. s. 75. ISBN978-1-78340-089-8. «In the late 1680s and early 1690s he is known to have been exporting 'Sheffield wares' including knives, penknives, spring knives and forks, some with tortoiseshell and others with horn handles, razors with silver capped handles, inkpots and ...»
