John G. Cramer, Robert L. Forward, Michael S. Morris, Matt Visser, Gregory Benford, and Geoffrey A. Landis, "Natural Wormholes as Gravitational Lenses," Phys. Rev. D51 (1995) 3117-3120
doi.org
dx.doi.org
Forward, R.L. (1984). „Roundtrip Interstellar Travel Using Laser-Pushed Lightsails”. J Spacecraft21 (2), 187–195. o. DOI:10.2514/3.8632.
G. A. Landis, "Interstellar Flight by Particle Beam," STAIF Conference on Innovative Transportation Systems for Exploration of the Solar System and Beyond, Albuquerque NM, 2001 február 11-15., AIP Conference Proceedings Volume 552, 393-396. Lásd még: Acta Astronautica, Volume 55, Issue 11, 2004 december, 931-934. o. (link)