W. T. Stobo and G. M. Fowler, “Sealworm (<i>Pseudoterranova decipiens</i>) dynamics in Sable Island grey seals (<i>Halichoerus grypus</i>): seasonal fluctuations and other changes in worm infections during the 1980s”, NAMMCOSP, vol. 3, pp. 129–147, Nov. 2001.