sci
hub

to open science
Kantelhardt, Jan W.; Bauer, Axel; Schumann, Aicko Y.; Barthel, Petra; Schneider, Raphael; Malik, Marek; Schmidt, Georg . (2007). Phase-rectified signal averaging for the detection of quasi-periodicities and the prediction of cardiovascular risk. Chaos: An Interdisciplinary Journal of Nonlinear Science, 17(1), 015112–. doi:10.1063/1.2430636 
An interview with Sci-Hub Founder Alexandra Elbakyan,Who exactly should pay for academic research