Seeds, M. A. (1986). Foundations of astronomy. Wadsworth.
Cita Chicago (17th ed.)Seeds, Michael A. Foundations of Astronomy. Belmont, Calif: Wadsworth, 1986.
Cita MLA (9th ed.)Seeds, Michael A. Foundations of Astronomy. Wadsworth, 1986.
Atenció: Aquestes cites poden no estar 100% correctes.