Spencer, E. W. (1988). Introduction to the structure of the earth. McGraw-Hill Book Company.
Lua i Stíl Chicago (17ú heag.)Spencer, Edgar W. Introduction to the Structure of the Earth. McGraw-Hill Book Company, 1988.
Lua MLA (8ú heag.)Spencer, Edgar W. Introduction to the Structure of the Earth. McGraw-Hill Book Company, 1988.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.