Herman, S. L., & Loper, O. E. (2012). Direct current fundamentals (8th ed.). Delmar Cengage Learning.
Lua i Stíl Chicago (17ú heag.)Herman, Stephen L., agus Orla E. Loper. Direct Current Fundamentals. 8th ed. Clifton Park, N.Y: Delmar Cengage Learning, 2012.
Lua MLA (9ú heag.)Herman, Stephen L., agus Orla E. Loper. Direct Current Fundamentals. 8th ed. Delmar Cengage Learning, 2012.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.