Sundari, D. S. ., Siswanto and Primastuti, E. . (2023) “Application of Progressive Muscle Relaxation and Deep Breathing in Working Pregnant Women to Reduce Stress Levels During the Covid-19 Pandemic”, Nusantara Science and Technology Proceedings. Malang, Indonesia, pp. 120-124. doi: 10.11594/nstp.2023.3516.