Burger, J. F. 1952. Sex physiology of pigs. Onderstepoort J. vet. Sci. Anim. Ind. Suppl. 2.
Heap, F. C., Lodge, G. A. and Lamming, G. E. 1967. Influence of plane of nutrition in early pregnancy on the survival and development of embryos in the sow. J. Reprod. Fert. 13: 269–269.
King, J. W. B. and Young, G. B. 1957. Maternal influences on litter size in pigs. J. agric. Sci., Camb. 48: 457–457.
Lasley, E. L. 1957. Ovulation, prenatal mortality and litter size in swine. J. Anim. Sci. 16: 335–335.
Lerner, E. H., Mayer, D. T. and Lasley, J. F. 1957. Early embryonic mortality in strain crossed gilts. Res. Bull. Mo. agric. Exp. Stn, No. 629.
Lodge, G. A. 1969. The effects of pattern of feed distribution during the reproductive cycle on the performance of sows. Anim. Prod. 11: 133–133.
Lodge, G. A., McDonald, I. and Macpherson, R. M. 1961. Weight changes in sows during pregnancy and lactation. Anim. Prod. 3: 269–269.
Longenecker, D. E., Watte, A. B. and Day, B. N. 1967. Similarity in the number of corpora lutea during two stages of pregnancy in swine. J. Anim. Sci. 26: 1497 (Abstr.).
O'Bannon, R. H., Wallace, H. D., Warnick, A. C. and Combs, G. E. 1966. Influence of energy intake on reproductive performance of gilts. J. Anim. Sci. 25: 706–706.
Pike, I. H. and Boaz, T. G. 1967. The effect of condition at service and plane of nutrition from service on ovulation, early foetal mortality and nitrogen utilization by the pregnant sow. In Proceedings of a Symposium on Nutrition of Sows. Pig Industry Development Authority, London.
Rathnasabapathy, V., Lasley, J. F. and Mayer, D. T. 1956. Genetic and environmental factors affecting litter size in swine. Res. Bull. Mo. agric. Exp. Stn, No. 615.
Reitmeyer, J. C. and Sorensen, A. M. 1965. Accessory corpora lutea in swine. J. Anim. Sci. 24: 928 (Abstr.).
Self, H. L., Grummer, R. H. and Casida, L. E. 1955. The effects of various sequences of full and limited feeding on the reproductive phenomena in Chester White and Poland China gilts. J. Anim. Sci. 14: 573–573.
Wise, F. S. and Robertson, G. L. 1953. Some effects of sexual age on reproductive performance in gilts. J. Anim. Sci. 12: 957 (Abstr.).
Zimmerman, D. R., Self, H. L. and Casida, L. E. 1957. Effect of flushing for various lengths of time on the ovulation rate of Chester White and Chester White-Poland China crossbred gilts. J. Anim. Sci. 16: 1099 (Abstr.).