Le, D., T. Nguyen, N. Phan, and Q. Thai. “A New Method of Electrodes Placement to Improve QRS Detection in Real-Time Stress ECG Acquisition”. Science and Technology Development Journal, Vol. 18, no. 2, June 2015, pp. 159-63, doi:https://doi.org/10.32508/stdj.v18i2.1088.