Song, W.; Wilbert, N. (1997). Morphological studies on some free living ciliates (Ciliophora: Heterotrichida, Hypotrichida) from marine biotopes in Qingdao, China, with descriptions of three new species: Holosticha warreni nov. spec, Tachysoma ovata nov. spec. and T. dragescoi nov. spec. European Journal of Protistology. 33(1): 48-62.
Morphological studies on some free living ciliates (Ciliophora: Heterotrichida, Hypotrichida) from marine biotopes in Qingdao, China, with descriptions of three new species: Holosticha warreni nov. spec, Tachysoma ovata nov. spec. and T. dragescoi nov. spec