Galileo Galilei, Sidereus Nuncius (Venice, (Italy): Thomas Baglioni, 1610), pages 15 and 16.
English translation: Galileo Galilei with Edward Stafford Carlos, trans., The Sidereal Messenger (London, England: Rivingtons, 1880), pages 42 and 43.
Thomas Wright, An Original Theory or New Hypothesis of the Universe … (London, England: H. Chapelle, 1750). From p.48: " … the stars are not infinitely dispersed and distributed in a promiscuous manner throughout all the mundane space, without order or design, … this phænomenon [is] no other than a certain effect arising from the observer's situation, … To a spectator placed in an indefinite space, … it [i.e., the Milky Way (Via Lactea)] [is] a vast ring of stars … " On page 73, Wright called the Milky Way the Vortex Magnus (the great whirlpool) and estimated its diameter at 8.64×1012 miles (13.9×1012 km).
Livingston, J. W. (1971). „Ibn Qayyim al-Jawziyyah: A Fourteenth Century Defense against Astrological Divination and Alchemical Transmutation”. Journal of the American Oriental Society91 (1): 96–103 [99]. DOI:10.2307/600445. ISSN0003-0279. JSTOR600445.
Curtis, H. D. (1988). „Novae in Spiral Nebulae and the Island Universe Theory”. Publications of the Astronomical Society of the Pacific100: 6. Bibcode1988PASP..100....6C. DOI:10.1086/132128.
Trimble, V. (1999). „Robert Trumpler and the (Non)transparency of Space”. Bulletin of the American Astronomical Society31 (31): 1479. Bibcode1999AAS...195.7409T.
Slipher, V. M. (1913). „The radial velocity of the Andromeda Nebula”. Lowell Observatory Bulletin1: 56–57. Bibcode1913LowOB...2...56S.
Curtis, H. D. (1988). „Novae in Spiral Nebulae and the Island Universe Theory”. Publications of the Astronomical Society of the Pacific100: 6. Bibcode1988PASP..100....6C. DOI:10.1086/132128.
Livingston, J. W. (1971). „Ibn Qayyim al-Jawziyyah: A Fourteenth Century Defense against Astrological Divination and Alchemical Transmutation”. Journal of the American Oriental Society91 (1): 96–103 [99]. DOI:10.2307/600445. ISSN0003-0279. JSTOR600445.
nap.edu
Weaver, H. F.. „Robert Julius Trumpler”. United States National Academy of Sciences. Pristupljeno January 5, 2007.
Livingston, J. W. (1971). „Ibn Qayyim al-Jawziyyah: A Fourteenth Century Defense against Astrological Divination and Alchemical Transmutation”. Journal of the American Oriental Society91 (1): 96–103 [99]. DOI:10.2307/600445. ISSN0003-0279. JSTOR600445.