1. 1) C. Edelstam and C. Palmer: Homing behaviour in gastropodes. Oikos, 2, 259-270 (1950).
2. 2) P. F. Newell: The nocturnal behaviour of slugs. Med. Biol. Ill., 16, 146-159 (1966).
3. 3) S. B. Cook: Experiments on homing in the limpet Siphonaria normalis. Anim. Behav., 17, 679-682 (1969).
4. 4) A. Cook, O. S. Bamford, J. D. B. Freeman, and D. J. Teideman: A study of the homing habit of the limpet. Anim. Behav., 17, 330-339 (1969).
5. 5) A. O. D. Willows: Learning in gastropod mollusks, in “Invertebrate Learning” (ed. by W. C. Corning, J. A. Dyal, and A. O. D. Willows), Vol. 2, Plenum Press, New York, 1973, pp. 247-249.