Dyfyniad APA
National Research Council (U.S.). Committee on NASA Astronomy Science Centers, National Research Council (U.S.). Space Studies Board, National Research Council (U.S.). Division on Engineering and Physical Sciences, & ebrary, Inc. (2007). Portals to the universe: The NASA astronomy science centers. The National Academies Press.
Dyfyniad Arddull Chicago
National Research Council (U.S.). Committee on NASA Astronomy Science Centers, National Research Council (U.S.). Space Studies Board, National Research Council (U.S.). Division on Engineering and Physical Sciences, and Inc ebrary. Portals to the Universe: The NASA Astronomy Science Centers. Washington, D.C.: The National Academies Press, 2007.
Dyfyniad MLA
National Research Council (U.S.). Committee on NASA Astronomy Science Centers, et al. Portals to the Universe: The NASA Astronomy Science Centers. The National Academies Press, 2007.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.