Retni, A. and Abdullah, F.M. 2026. Effectiveness of the Stimulation of Endorphin, Oxytocin, and Serotonin (SPEOS) Method in Improving Sleep Quality among Postpartum Women: A Quasi-Experimental Study in Primary Maternal Healthcare in Gorontalo, Indonesia. Journal of Health and Nutrition Research. 5, 2 (Aug. 2026), 1048–1057. DOI:https://doi.org/10.56303/jhnresearch.v5i2.1469.