Warttig SL, Forshaw MJ, South J, White AK. New, normative, English-sample data for the Short Form Perceived Stress Scale (PSS-4). J Health Psychol. 2013 Dec;18(12):1617-28. doi: 10.1177/1359105313508346
Webster AJ, Saville C, Church BM, Gnanasakthy A, Moss R. Some effects of different rearing systems on health, cleanliness and injury in calves. Vet J. 1985 Sep;141(5):472-83.
Webster AJ, Saville C, Church BM, Gnanasakthy A, Moss R. The effect of different rearing systems on the development of calf behaviour. Vet J. 1985 May;141(3):249-64.