Harlan, E.A. «A Star-Trail Telescope for Astronomical Site-Testing». Publications of the Astronomical Society of the Pacific, 77, 457, agost 1965, pàg. 246–252. Bibcode: 1965PASP...77..246H. DOI: 10.1086/128210.
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NASA Johnson Space Center. «ISS Star Trails», May–June 2012.
Harlan, E.A. «A Star-Trail Telescope for Astronomical Site-Testing». Publications of the Astronomical Society of the Pacific, 77, 457, agost 1965, pàg. 246–252. Bibcode: 1965PASP...77..246H. DOI: 10.1086/128210.