1. Top 15 Global Therapeutic Classes 2008 https://www.imshealth.com/deployedfiles/imshealth/Global/Content/StaticFile/Top_Line_Data/Global_Top_15_Therapy_Classes.pdf
2. Top 200 drugs of 2012;Bartholow;Pharm Times,2013
3. Top 20 Global Products 2012, IMS Health MIDAS http://www.imshealth.com/deployedfiles/ims/Global/Content/Corporate/Press%20Room/Top-Line%20Market%20Data%20&%20Trends/Top_20_Global_Products_2012_2.pdf
4. The value of branded proton pump inhibitors: formulary considerations;Peura;PT,2011
5. Omeprazole (Losec) Capsule Package Insert http://www.hsa.gov.sg