LINKOPINGS UNIVERSITY MEDICAL 527,745 DISSERTATIONS No.35 DAHLGREN SUNE , Shortening or labour especially the period of dilatation with low frequency vibrations against cervix uteri. A clinical study. Prom the Swedish by Lars Schullstrom Linköping 1976 8° s. 103, il. Acta Obstetricia et Gynecologica Scandinavie suppl. 55 Linkopings University Medical Dissertations no 35