Further study on the influence of primiparous age and litter number on the mammary tumor age in mice.
D000818:Animals; D000831:Animals, Newborn; D004971:Estrus; D005260:Female; D008325:Mammary Neoplasms, Experimental; D008433:Mathematics; D051379:Mice; D011247:Pregnancy; D013997:Time Factors; D014626:Vaginal Smears