Shirley, T. C.; Storch, V. (1999). "Halicryptus higginsi n.sp. (Priapulida): A Giant New Species from Barrow, Alaska". Invertebrate Biology. Quyển 118 số 4. tr. 404–413. doi:10.2307/3227009. JSTOR3227009.
Aarnio, K.; Bonsdorff, E.; Norkko, A. (1998). "Role of Halicryptus spinulosus (Priapulida) in structuring meiofauna and settling macrofauna". Marine Ecology Progress Series. Quyển 163. tr. 145. doi:10.3354/meps163145.
Shirley, T. C.; Storch, V. (1999). "Halicryptus higginsi n.sp. (Priapulida): A Giant New Species from Barrow, Alaska". Invertebrate Biology. Quyển 118 số 4. tr. 404–413. doi:10.2307/3227009. JSTOR3227009.