Παραπομπή APA

Pentz, M. J. (1975). Earth history I and II S100 26 and 27. Open University Press.

Παραπομπή Chicago Style

Pentz, M. J. Earth History I and II S100 26 and 27. Open University Press, 1975.

Παραπομπή MLA

Pentz, M. J. Earth History I and II S100 26 and 27. Open University Press, 1975.