Duwal, S., and R. Saiju. “Outcomes of External Dacryocystorhinostomy and Endoscopic Endonasal Dacryocystorhinostomy in the Management of Nasolacrimal Duct Obstruction”. Nepalese Journal of Ophthalmology, vol. 7, no. 1, Sept. 2015, pp. 39-46, doi:10.3126/nepjoph.v7i1.13165.