Gallardo, Jose Manuel, Giannina Bellone, Rubén Acevedo, and Marcelo Risk. 2021. “Ultra-Short-Term Heart Rate Variability Analysis: Comparison Between Poincaré and Frequency Domain Methods”. IEEE Latin America Transactions 20 (1):180-88. https://latamt.ieeer9.org/index.php/transactions/article/view/5433.