Concentrations of catecholamines, ascorbic acid, progesterone and oxytocin in the corpora lutea of cyclic and pregnant cattle Grazyna Miszkiel, Dariusz Skarzynski, Marek Bogacki and Jan Kotwica Reprod. Nutr. Dev., 39 4 (1999) 509-516 DOI: 10.1051/rnd:19990410