O. Pikatan, D. K. Indrasari Utami, and A. A. A. P. Laksmidewi, “Heart Rate Variability in Insomnia and Poor Sleep Quality versus Controls: An Updated Meta-Analysis of Case-Control and Cross-Sectional Studies Using Standardised Mean Differences”, sjn, vol. 3, no. 2, pp. 121-131, Jul. 2026.