Wehrhahn, C Former Department Information Processing in Insects, Max Planck Institute for Biological Cybernetics, Max Planck Society; Max Planck Institute for Biological Cybernetics, Max Planck Society;
https://link.springer.com/content/pdf/10.1007/BF00344166.pdf (Publisher version)
Wehrhahn, C. (1976). Evidence for the role of retinal receptors R 7/8 in the orientation behaviour of the fly. Biological Cybernetics, 21(4), 213-220. doi:10.1007/BF00344166.