1. Bengtsson A-C, Svendsen J, Persson G: Jämförande undersökning av dräktiga suggor i 4 olika inhysningssystem: Beteendestudier och renhetsstudier. (Comparison of four types of housing for sows in gestation: Behaviour studies and hygiene studies). Report 36. Dept. Farm Buildings, Swedish Univ. Agric. Sci. Lund 1983.
2. Bille N, Nielsen NC, Larsen JL, Svendsen J: Preweaning mortality in pigs. II. The perinatal period. Nord. Vet.-Med. 1974, 26, 294–313.
3. Björklund N-E, Svendsen J, Svendsen LS: Histomorphological studies of the perinatal pig: The unaffected pig. Acta vet. scand. 1987, 28, 93–104.
4. Coussement W, Ducatelle R, Hoorens J: Splayleg in piglets. Histology and histochemistry. Proceedings, 8th Int. Pig. Vet. Soc. Congr., Ghent 1984, p. 282.
5. DeRoth L, Downie HG: Evaluation of viability of neonatal swine. Canad. vet. J. 1976, 17, 275–279.