Senanayaka ,Nimal විද්යා අධ්යාපන පෙළ අංක 8 = vidya adhyana peLa 8 - Colombo: Jathika Pusthakala Sewa mandalaya, 1991. - 46p.; 23 cm. ISBN: 955-9011-62-6 Subjects--Topical Terms: Health ScienceScience Dewey Class. No.: 610.7 / SEN