Clark, S. P. (1971). Structure of the earth. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Clark, Sydney P. Structure of the Earth. Englewood Cliffs, N.J.: Prentice-Hall, 1971.
Lua MLA (9ú heag.)Clark, Sydney P. Structure of the Earth. Prentice-Hall, 1971.
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