1. World Health OrganizationWHO fact sheet20172017-12-01Cardiovascular diseases (CVDs)
http://www.who.int/mediacentre/factsheets/fs317/en/
2. American Heart Association20152016-09-09Electrocardiogram (ECG or EKG)
http://www.heart.org/HEARTORG/Conditions/HeartAttack/DiagnosingaHeartAttack/Electrocardiogram-ECG-or-EKG_UCM_309050_Article.jsp
3. Recommendations for the Standardization and Interpretation of the Electrocardiogram
4. Learning and teaching electrocardiography in the 21st century: A neglected art