1. Very early abortion using syringe as vacuum source;Karman;Lancet,1972
2. Early abortion without cervical dilatation, pump or syringe aspiration;Margolis;J Reprod Med.,1972
3. Suction curettage for menstrual regulation;Brenner,1973
4. Aspiration without cervical dilatation;Goldsmith;Am J Obstet Gynecol.,1971
5. Modified cervical block for elective abortion procedures;Walden;Obstet Gynecol.,1973