- Alfred Hoblitzelle Clifford : July 11, 1908-December 27, 1992,
*Semigroup Forum***46**(2) (1993), 137.

- K H Hofmann and J D Lawson, Linearly ordered semigroups: historical origins and A H Clifford's influence,
*Semigroup theory and its applications, New Orleans, LA, 1994*(Cambridge Univ. Press, Cambridge, 1996), 15-39.

- D D Miller, Reminiscences of a friendship,
*Semigroup theory and its applications, New Orleans, LA, 1994*(Cambridge Univ. Press, Cambridge, 1996), 1-2.

- D D Miller, A H Clifford : the first sixty-five years, Collection of articles dedicated to Alfred Hoblitzelle Clifford on the occasion of his 65th birthday and to Alexander Doniphan Wallace on the occasion of his 68th birthday,
*Semigroup Forum***7**(1-4) (1974), 4-9.

- G B Preston, A H Clifford's work on unions of groups,
*Semigroup theory and its applications, New Orleans, LA, 1994*(Cambridge Univ. Press, Cambridge, 1996), 5-14.

- G B Preston, A H Clifford : an appreciation of his work on the occasion of his sixty-fifth birthday,
*Semigroup Forum***7**(1-4) (1974), 32-57.

- J Rhodes, The relationship of Al Clifford's work to the current theory of semigroups,
*Semigroup theory and its applications, New Orleans, LA, 1994*(Cambridge Univ. Press, Cambridge, 1996), 43-51.