Hirose E, Kimura S, Itoh T, Nishikawa J.
Biol Bull. 1999 Feb;196(1):113-20 doi:10.2307/1543173
Tunic morphology and cellulosic components of pyrosomas, doliolids, and salps (thaliacea, urochordata).
Shows synaptomorphy of the tunic in ascidians and thaliaceans.