University of Illinois (Urbana-Champaign campus), Elementary School Science Project, Atkin, J. M., & Wyatt, S. P. (1969). The University of Illinois astronomy program. Harper & Row.
Dyfyniad Arddull ChicagoUniversity of Illinois (Urbana-Champaign campus), Elementary School Science Project, J. Myron Atkin, and Stanley P. Wyatt. The University of Illinois Astronomy Program. New York: Harper & Row, 1969.
Dyfyniad MLAUniversity of Illinois (Urbana-Champaign campus), et al. The University of Illinois Astronomy Program. Harper & Row, 1969.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.