Reference

J. Génermont, C. Demar, F. Fryd-Versavel, H. Tuffrau, Michel Tuffrau (1992): Polygenic control of an all-or-non morphological trait in Euplotes (Ciliata, Hypotrichea). Evolutionary significance of naturally occurring morphologic variation in ciliates – Genet? – 24: 89 - 105.