Trivedi, M., Sreedharan, S., Nair, S., Anees, C., Unnikrishnan, J., Sarma, P., & Radhakrishnan, A. (1969). Central Disorders of Hypersomnolence in Children and Adults: A Comparative Study from South India. Annals of Indian Academy of Neurology, 22(4), 442-446. https://doi.org/10.4103/aian.AIAN_293_18 (Original work published 1969)