Physicists have long sought a grand unified theory, since scientists have always preferred theories with the fewest of elements.1
1. Alan Lightman, Ancient Light: Our
Changing View of the Universe (Cambridge:
Harvard University Press, 1991), 106.
Lightman, Alan. Ancient Light: Our Changing
View of the Universe. Cambridge: Harvard
University Press, 1991.
If the next reference is to the same source, substitute the abbreviation Ibid. (from the Latin ibidem, meaning "in the same place") for the work. Unless the reference is to the same page or pages listed in the preceding reference, indicate the page number after a comma and a space.
2. Ibid., 152
Subsequent nonconsecutive notes to the same reference are then given in a brief format.
6. Lightman, 127