1. A far-reaching interpolation;Macau lay;Heart Lung,1989
2. Concealed conduction;Tay;Heart Lung,1994
3. Extrasystoles and allied arrhythmias;Scherf,1973
4. Pearls & pitfalls in electrocardiography;Marriott,1990
5. How long can the P-R interval be?;Rusterholz;Am J Noninvas Cardiol,1994