American Psychological Association
Humphreys, Christmas ( 1973 ). Concentration and Meditation`s Manual of Mind Development ( 00 ed. ). Watkins.
Modern Language Association
Humphreys, Christmas. Concentration and Meditation`s Manual of Mind Development . Watkins. 1973
Chicago Citation
Humphreys, Christmas. Concentration and Meditation`s Manual of Mind Development . 00 .London
: Watkins, 1973.
American Medical Association
Humphreys, Christmas. Concentration and Meditation`s Manual of Mind Development . Watkins; 1973.