Gaya APA
International Olympiad on Astronomy and Astrophhysics Problems Volume 1 2007-2012. (2016).
Nusa Tenggara Timur:
PT. Trisula Adisakti.
Gaya MLA
International Olympiad on Astronomy and Astrophhysics Problems Volume 1 2007-2012.
-.
Nusa Tenggara Timur:
PT. Trisula Adisakti,
2016.
Text.