Nicolson, Iain
The universe
Horus Editions, 1995
Buku Referensi
Oparin, A.
The universe
Foreign Languages Publishing House, 1960
Buku Teks
The universe grasper
Artikel Jurnal
The universe of meanings
Artikel Jurnal
Krauskopf, Konrad B.
The physical universe
McGraw-HIll, 2000
Buku Teks SO