Sumber:

• https://www.baby-chick.com/what-is-a-peanut-ball/
• https://www.bellybelly.com.au/birth/peanut-ball-for-labour/
• https://www.healthline.com/health/pregnancy/peanut-ball#claims
• https://www.lamaze.org/Connecting-the-Dots/peanut-balls-for-labor-a-valuable-tool-for-promoting-progress