de Witte, B., Loyens, R, Robeaux, R & Clarys, J. P. (1988). The activity of trunk muscles in paraplegic patients after breaststroke initiation. In B. E. Ungerechts, K. Wilke & K. Reischle (Hrsg.), Swimming Science V (International Series of Sport Sciences, Volume 18, S. 319-331). Champaign: Human Kinetics Books.

de Witte, B., Loyens, R., Robeaux, R., & Clarys, J. P. (1988). The activity of trunk muscles in paraplegic patients after breaststroke initiation. Swimming Science V, 319-331.

de Witte, B., R. Loyens, R. Robeaux, und J. P. Clarys. "The Activity of Trunk Muscles in Paraplegic Patients After Breaststroke Initiation." Swimming Science V 1988: 319-331.

de Witte, B., et al. "The Activity of Trunk Muscles in Paraplegic Patients After Breaststroke Initiation." Swimming Science V, 1988, pp. 319-331.