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Sandnabba N. K.; Santtila P.; Nordling N.; Beetz A. M.; Alison L. (November 2002). "Characteristics of a Sample of Sadomasochistically-oriented Males with Recent Experience of Sexual Contact with Animals". Deviant Behavior. 23 (6): 511–529. doi:10.1080/01639620290086503. S2CID144188679.