Tugas Individu 1_8_M. Afif Vargas Pramono

(1) Longman Pocket English Dictionary. Edinburgh Gate, Harlow, Essex, England: Pierre-Henri Cousin; 2001. Doctor; p.153.

(2) Oxford Minireference Dictionary & Thesaurus. United States: Oxford University Press Inc., New York; 1995. Doctor; p. 177.

(3) Lawrence, Christopher. The Lancet; London Vol. 377, Iss. 9781,  (Jun 4-Jun 10, 2011): 1910.