Williams, G. (1966). A study of a seminal defect in Hereford bulls and also of the effect on fertility of the movement of cattle to a new environment. University of London.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Williams, Gareth. A Study of a Seminal Defect in Hereford Bulls and Also of the Effect on Fertility of the Movement of Cattle to a New Environment. University of London, 1966.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Williams, Gareth. A Study of a Seminal Defect in Hereford Bulls and Also of the Effect on Fertility of the Movement of Cattle to a New Environment. University of London, 1966.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.