Betel Quid, Smoking and Alcohol Dependency among Patients with Oral Potentially Malignant Disorders and Oral Cancer in Sri Lanka; A Preliminary Case-control Study - R. Sumithrarachchi, Sumali; Pemasiri, W.A.Udari.C.; Pathiranage, A.M.S. Deepanie.; Jayasooriya, Primali R. (Asian Pacific Journal of Cancer Biology, 2021)