Bofill, J.A., O.A. Rust, S.J. Schorr, R.C. Brown. "A randomized prospective trial of the obstetric forceps versus the M-cup vacuum extractor." American Journal of Obstetrics and Gynecology 175/5 (November 1996): 1325–1330.

Bofill, J.A., O.A. Rust, S.J. Schorr, R.C. Brown. "A randomized prospective trial of the obstetric forceps versus the M-cup vacuum extractor." American Journal of Obstetrics and Gynecology 175/5 (November 1996): 1325–1330.