1. Graviditetsregistret.Graviditetsregistrets årsrapport2020.[The pregnancy register's annual report 2020]. In Swedish Internet 20. Available from:https://www.medscinet.com/GR/uploads/hemsida/dokumentarkiv/GR%20%C3%85rsrapport%202020%203.0.pdf
2. Vladic‐Stjernholm YWAA‐WI.Instrumental delivery by vacuum extraction: advice for clinical recommendations (in Swedish): Löf 2017[Available from:https://lof.se/filer/Instrumentell‐forlossning‐med‐sugklocka.pdf.]
3. Assisted Vaginal Birth
4. The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG).Instrumental vaginal birth. RANZCOG web page;2020.https://ranzcog.edu.au/wp‐content/uploads/2022/05/Instrumental‐vaginal‐birth.pdf
5. Modification of Malmstrom's vacuum extractor.