Gaya APA

Osterbrock, D, E., Ferland, G, J. (2006). Astrophysics of Gaseous Nebulae and Active Galactic Nuclei second edition (Second Edition). USA: University Science Books.

Gaya MLA

Osterbrock, Donald, E.., Ferland, Gary, J.. "Astrophysics of Gaseous Nebulae and Active Galactic Nuclei second edition". Second Edition USA: University Science Books, 2006. Text.