REFERENCES
Allen, R.J., Hamaker, J.P., Wellington, K.J.:
1974, Astron. Astrophys. 31, 71
Bosma, A.:
1978a, Ph.D. dissertation, University of Groningen
Bosma, A.:
1978b, Astron. Astrophys., submitted
Burbidge, E.M., Burbidge, G.R., Prendergast, K.H.:
1960, Astrophys. J. 131, 282
Fish, R.A.:
1961, Astrophys. J. 134, 880
Gallouët, L., Heidmann, N., Dampierre, F.:
1973, Astron. Astrophys. Suppl. 12, 89
Högbom, J.A.
1974, Astron. Astrophys. Suppl. 15, 417
Högbom, J.A., Brouw, W.N.:
1974, Astron. Astrophys. 33, 289
Holmberg, E.:,
1958, Medd. Lund Obs. Ser. II no. 136
Hummel, E., Bosma, A.:
1978, in preparation
Hunter, C., Toomre, A.:
1969, Astrophys. J. 155, 747
Kahn, F.D., Woltjer, L.:
1959, Astrophys. J. 130, 705
Kruit, P.C. van der:
1973, Astron. Astrophys. 29, 231
Kruit, P.C. van der:
1978, in preparation
Kruit, P.C. van der, Bosma, A.:
1978, Astron. Astrophys., submitted
Lindblad, B., Delhaye, J.:
1949, Stockholm Ann. 15, no. 9
Nilsson, P.:
1973, Uppsala General Catalogue of Galaxies,
Nova Acta Regiae Societatis Scientiatum Upsaliensis Ser. V.: A, Vol. I
Nordsieck, K.H.:
1973, Astrophys. J. 184, 719
Rogstad, D.H., Rougoor, G.W., Whiteoak, J.B.:
1967, Astrophys. J. 150, 9
Rogstad, D.H., Lockhart, II.A., Wright, M.C.H.:
1974, Astrophys. J. 193, 309
Rogstad, D.H., Wright, M.C.H., Lockhart, I.A.:
1976, Astrophys. J. 204, 703
Sancisi, R.:
1976, Astron. Astrophys. 53, 159
Sandage, A.:
1961, The Hubble Atlas of Galaxies, Carnegie
Institution of Washington
Shostak, G.S.:
1978, Astron. Astrophys. (in press)
Shu, F.H., Stachnik, R.B., Yost, J.C.:
1971, Astrophys. J. 166, 465
Toomre, A.: 1977, in
Topics in Interstellar Matter, ed. H. van
Woerden (Reidel Dordrecht), p 259
Vaucouleurs, G. de:
1958, Astrophys. J. 127, 487
Vaucouleurs, G. de, Vaucouleurs, A. de, Corwin,
H.G.:
1976, Second Reference Catalogue of Bright Galaxies,
University of Texas Press, Austin