1. Campbell, A.W.: 1982, Observatory 102, 195.
2. Cannon, R.D.: 1984, this volume, p. 25.
3. Dawe, J.A.: 1984, this volume, p. 193.
4. Malin, D.F.: 1977, ASS Photobulletin No. 16, p. 10.
5. Malin, D.F.: 1978a, ‘Modern Techniques in Astronomical Photography’, ed. West & Eudier, p. 107.