1. Arp, H. 1968,Astrophys. J.,152, 1101.
2. Arp, H. 1973,The Redshift Controversy, Ed. G. B. Field, W. A. Benjamin, Massachusetts.
3. Arp, H. 1978,Problems of Physics and Evolution of the Universe, Ed. V. L. Mirzoyan, Armenian Acad. Sci., Yerevan, p. 65
4. Arp, H. 1981, inProc. second ESO/ESA Workshop: Optical Jets in Galaxies, ESA, Netherlands, p. 53.
5. Arp, H. 1983, inGroups, Concentrations and Associations of Quasars, Institut d’Astrophysique Univ. Liege, p. 307.