APA
Gunasinghe R. M., Wikcramasinghe I. R., Liyanage L. S. G., Tennakoone M. M. S. G. K., Sumanasekara G. U., Hettiarachchi R. D., Abeydeera D., Vithanage J. D., Sirikanthi W. D. M., Alahakoone M. D. & Sumanawathie P. D. (1986). Physics: geometrical optics. Nugegoda: The open university of Sri Lanka.
Chicago
Gunasinghe R M, Wikcramasinghe I R, Liyanage L S G, Tennakoone M M S G K, Sumanasekara G U, Hettiarachchi R D, Abeydeera D.R, Vithanage J D, Sirikanthi W D M, Alahakoone M D.P and Sumanawathie P D. 1986. Physics: geometrical optics. Nugegoda: The open university of Sri Lanka.
Harvard
Gunasinghe R. M., Wikcramasinghe I. R., Liyanage L. S. G., Tennakoone M. M. S. G. K., Sumanasekara G. U., Hettiarachchi R. D., Abeydeera D., Vithanage J. D., Sirikanthi W. D. M., Alahakoone M. D. and Sumanawathie P. D. (1986). Physics: geometrical optics. Nugegoda: The open university of Sri Lanka.
MLA
Gunasinghe R M, Wikcramasinghe I R, Liyanage L S G, Tennakoone M M S G K, Sumanasekara G U, Hettiarachchi R D, Abeydeera D.R, Vithanage J D, Sirikanthi W D M, Alahakoone M D.P and Sumanawathie P D. Physics: geometrical optics. Nugegoda: The open university of Sri Lanka. 1986.