Journal Article
                        
                        Wirth, James P, Nicolai  Petry, Sherry A Tanumihardjo, Lisa M Rogers, Erin  McLean, Alison  Greig, Greg S Garrett, Rolf DW  Klemm, and Fabian  Rohner.  
"Vitamin A supplementation programs and country-level evidence of vitamin A deficiency." Nutrients 9, no. 3 (2017).