Motz, L., & Duvven, A. (1967). Essentials of Astronomy. Columbia University.
Cita Chicago Style (17a ed.)Motz, Lloyd, y Anneta Duvven. Essentials of Astronomy. Columbia University: Columbia University, 1967.
Cita MLA (9a ed.)Motz, Lloyd, y Anneta Duvven. Essentials of Astronomy. Columbia University, 1967.
Precaución: Estas citas no son 100% exactas.