REFERENCES
ABELL, G. 0.,
Problems of Extra-Galactic Research, I. A. U. Symposium 15
(ed. G. C. McVittie), p. 213. Macmillan, New York (1962).
ABELL, G. 0.,
Ap. J. 140, 1624 (1964).
ABELL, G. 0., and EASTMOND, S.,
A. J. 73, S 161 (1968).
ARP, H.,
Ap. J. 148, 321 (1967).
ARP; H.,
P.A.S.P. 80, 129 (1968a).
ARP; H.,
Astrophyzika 4, 59 (1968b).
VAN DEN BERGH, S.,
A. J. 71, 922 (1966).
VAN DEN BERGH, S.,
J. R. astr. Soc. Can. 62, 145, 219 = Commun. David
Dunlap Obs., No. 195 (1968).
BURBIDGE, E. M., and BURBIDGE, G. R.,
Ap. J. 142, 1351 (1965).
HOLMBERG, E.,
Ap. J. 92, 200 = Contr. Mt Wilson -Obs., No. 633 1940).
HOLMBERG, E.,
Medd. Lunds astr. Obs., Ser. II, No. 128 (1950).
HOLMBERG, E.,
Medd. Lunds astr. Obs., Ser. II, No. 136 (1958).
HOLMBERG, E.,
Ark. Astr. 3, 387 = Uppsala astr. Obs. Medd., No. 148 (1964).
HUBBLE, E.,
Ap. J. 79, 8 = Contr. Mt Wilson Obs., No. 485 (1934).
HUBBLE, E.,
Ap. J. 84, 158 = Contr. Mt Wilson Obs:, No. 548 (1936).
HUMASON, M. L., MAYALL, N. U., and SANDAGE, A. R.,
A. J. 61, 97 (1956).
KIANG, T.,
M.N.R.A.S. 122, 263 (1961).
LIMBER, D. N.,
Ap. J. 131, 168 (1960).
LYNDS, C. R., and SANDAGE, A. R.,
Ap. J. 137, 1005 (1963).
MINKOWSKI, R. L., and ABELL, G. O.,
The National Geographic Society - Palomar Observatory
Sky Survey in Basic Astronomical Data (ed. K. Aa. Strand),
p. 481. Univ. Chicago Press, Chicago (1963).
PEEBLES, P. J. E., and PARTRIDGE, R. B.,
Ap. J. 148, 713 (1967).
REINMUTH, K.,
Veröff. Sternw. Heidelberg, Bd. 9 (1926).
SANDAGE, A.,
Ap. J. 152, L 149 (1968).
SÉRSIC, J. L., and PASTORIZA, M.,
P.A.S.P. 79, 152 (1967).
SÉRSIC, J. L.,
Bull. astr. Inst. Csl. 19, 105 (1968).
SHANE, C. D., and WIRTANEN, C. A.,
Publ. Lick Obs., Vol. XXII, Part I (1967).
SHAPLEY, H., and AMES, A.,
Ann. Harv. Coll. Obs. 88, 41 (1932).
SOLINGER, A. B.,
Ap. J. 155, 403 (1969).
SWJAGINA, E. W.,
A. J. UdSSR 43, 34 (1966).
DE VAUCOULEURS, G., and DE VAUCOULEURS, A.,
Reference Catalogue of Bright Galaxies, Univ. Texas Press, Austin =
Univ. Texas Monogr. Astr., No. 1 (1964).
DE VAUCOULEURS, A., and DE VAUCOULEURS, G.,
A. J. 72, 730 (1967).
WALKER, M. F.,
Ap. J. 151, 71 (1968a).
WALKER, M. F.,
Astrophys. Letters 2, 65 (1968b).
ZONN, W.,
Acta astr. 18, 335 (1968).
ZWICKY, F.,
Morphological Astronomy, Springer-Verlag, Berlin,
p. 171 (1957).
ZWICKY, F.,
Ap. J. 140, 1626 (1964).
ZWICKY, F., HERZOG, E., and WILD, P.,
Catalogue of Galaxies and of Clusters of Galaxies,
Vol. I. Cal. Inst. Techn., Pasadena (1961).
ZWICKY, F., and HERZOG, E.,
Catalogue etc., Vol. II, Cal. Inst. Techn., Pasadena
(1963).
ZWICKY, F., KARPOWICZ, M., and KOWAL, C. T.,
Catalogue etc., Vol. V, Cal. Inst. Techn., Pasadena (1965).
ZWICKY, F., and HERZOG, E.,
Catalogue etc., Vol. III, Cal. Inst. Techn.,
Pasadena (1966).
ZWICKY, F., and HERZOG, E.,
Catalogue etc., Vol. IV, Cal. Inst. Techn., Pasadena
(1968).
ZWICKY, F., and KOWAL, C. T.,
Catalogue etc., Vol. VI, Cal. Inst. Techn., Pasadena
(1968).