Spiegel, L. (1991). Applied Statics And Strength Of Materials Leonard Spiegel; George F. Limbrunner. Macmilan.
Lua i Stíl Chicago (17ú heag.)Spiegel, Leonard. Applied Statics And Strength Of Materials Leonard Spiegel; George F. Limbrunner. Macmilan, 1991.
Lua MLA (8ú heag.)Spiegel, Leonard. Applied Statics And Strength Of Materials Leonard Spiegel; George F. Limbrunner. Macmilan, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.