Exemplo:
[#] J. P. Wilkinson, "Nonlinaer resonant circuit devices", U.S. Patente 3 624 125, 16 xul., 1990.
Exemplo:
[#] Screwless clip mounted computer drive, por D. Williams. (26 abr., 2005). U.S. Patent 6,885,550 [En liña]. Dispoñible en: http://patft.uspto.gov/netacgi/6,885,550