1. Punin, M.Yu., Gistologicheskaya organizatsiya kishechnykh epiteliev priapulid, brakhiopod, dvustvorchatykh mollyuskov i polikhet (The Histology of Intestine Epithelia of Priapulida, Brachiopoda, Bivalvia, and Polychaeta), St. Petersburg: Nauka, 1991.
2. Punin, M.Yu., Kishechnaya regulyatornaya sistema bespozvonochnykh zhivotnykh i ee predpolagaemaya evolyutsiya u mnogokletochnykh (The Intestinal Regulatory System of Invertebrates and Its Presumed Evolution in Multicellular Organisms), St. Petersburg, 2001.
3. Filimonova, G.F., Funktsional’naya morfologiya pishchevaritel’noi sistemy iglokozhikh (The Functional Morphology of the Digestive System in Echinodermata), Leningrad: Nauka, 1979.
4. Billingsley, P.F., Ann. Rev. Entomol., 1990, vol. 35, pp. 219–248.
5. Balashev, I.V., Nozdrachev, A.D., and Skopichev, V.G., Dokl. Akad. Nauk, 1992, vol. 325, no. 3, pp. 623–625.