Books, Brochures, and Chapters>Book:  Newton, Sir Isaac (1718), Opticks: Or, A Treatise of the Reflections, Refractions, Inflections and Colours of Light. ..., Retrieved on 2014-06-21

Source Material [books.google.com]

Periodicals>Journal Article:  Al-Haitham, Ibn and Winter, H. J. J. (1950), A Discourse of the Concave Spherical Mirror by Ibn Al-Haitham, Journal of the Royal Asiatic Society of Bengal, 16, 2., Retrieved on 2011-09-03