P. E.  Stueben, ?Analytical catalogue of Westpalearctic Cryptorhynchinae. Part 1: Kyklioacalles, Onyxacalles, Dichromacalles, Calacalles, Echinodera (Col.: Curculionidae: Cryptorhynchinae)?, vol. 2. pp. 59-119, 2001.

P. E.  Stueben, ?Analytical catalogue of Westpalearctic Cryptorhynchinae. Part 1: Kyklioacalles, Onyxacalles, Dichromacalles, Calacalles, Echinodera (Col.: Curculionidae: Cryptorhynchinae)?, Snudebiller, vol. 2. pp. 59-119, 2001.

P. E.  Stueben, Behne, L., and Bahr, F., ?Analytical catalogue of Westpalearctic Cryptorhynchinae. Part 1: Kyklioacalles, Onyxacalles, Dichromacalles, Calacalles, Echinodera (Col.: Curculionidae: Cryptorhynchinae)?, Snudebiller, vol. 2. pp. 59-119, 2001.