Παραπομπή APA

Engelbert, P. (1997). Astronomy and Space: From the Big Bang to the Big Crunch. U. X. L.

Παραπομπή Chicago Style

Engelbert, Phillis. Astronomy and Space: From the Big Bang to the Big Crunch. New York: U. X. L, 1997.

Παραπομπή MLA

Engelbert, Phillis. Astronomy and Space: From the Big Bang to the Big Crunch. U. X. L, 1997.