Sundari, Dini Sri, Siswanto, and Emiliana Primastuti. 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, December. Malang, Indonesia, 120-24. https://doi.org/10.11594/nstp.2023.3516.