1. Canine gestation length: variation related to time of mating and fertile of sperm;Concannon;Am J Vet Res,1983
2. Clinical and endocrine correlates of canine ovarian cycles and pregnancy;Concannon,1986
3. Canine pregnancy and parturition;Concannon;Vet Clin North Am Small Anim Pract,1986
4. Concannon PW. Canine pregnancy: predicting parturition and timing events of gestation. In: Concannon P, England G, Verstegen J, editors. Recent advances in small animal reproduction. International Veterinary Information Service; 2000 (www.ivis.org).
5. Reproductive hormone concentrations during estrus, pregnancy, and pseudopregnancy in the Labrador bitch;Chakraborty;Theriogenology,1987