@article {tan2013ecg,
	title = {ECG P wave abnormalities},
	journal = {Singapore medical journal},
	volume = {54},
	number = {1},
	year = {2013},
	pages = {4{\textendash}7},
	author = {Tan, Li Ling and Teo, Swee Guan and Poh, Kian Keong}
}