Nasution SS, Erniyati E, Hariati H. Effectiveness of Progressive Muscle Relaxation on The Complete Opening Time during Normal Labor. Open Access Maced J Med Sci [Internet]. 2020 Aug. 20 [cited 2024 May 6];8(B):608-11. Available from: https://oamjms.eu/index.php/mjms/article/view/4145