Gaya APA

Inc, E, B., (ed), R, M, H. (). Great books of the western world 16 Ptolemy, Copernicus, Kepler . : encyclopaedia britannica.

Gaya MLA

Inc, Encyclopaedia, Britannica., (ed), Robert, Maynard, Hutchins. "Great books of the western world 16 Ptolemy, Copernicus, Kepler". : encyclopaedia britannica, . Text.