Sapkota, K, DK Sah, S Bhattarai, AK Sharma, JK Shrestha, and DN Shah. 2011. “Effectiveness of Pencil Push up Therapy in Patients With Convergence Insufficiency: A Pilot Study”. Health Renaissance 9 (3):157-61. https://doi.org/10.3126/hren.v9i3.5583.