Contreras, Francisco. “Ophthalmology in Peru and South America”. Seminars in Ophthalmology, vol. 8, no. 3, 1993, pp. 183-5, https://doi.org/10.3109/08820539309060231.
Contreras, F. (1993). Ophthalmology in Peru and South America. Seminars in Ophthalmology, 8(3), 183-185. https://doi.org/10.3109/08820539309060231
Contreras F. Ophthalmology in Peru and South America. Seminars in Ophthalmology. 1993;8(3):183-5.