Bootsma, J. (1975). Liquid-lubricated spiral-groove bearings.
Lua i Stíl Chicago (17ú heag.)Bootsma, J. Liquid-lubricated Spiral-groove Bearings. 1975.
Lua MLA (8ú heag.)Bootsma, J. Liquid-lubricated Spiral-groove Bearings. 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.