Kotter, J. P. C. (2002). Heart of Change. Harvard Bus. School.
Dyfyniad Arddull ChicagoKotter, John P; Cohen. Heart of Change. Boston: Harvard Bus. School, 2002.
Dyfyniad MLAKotter, John P; Cohen. Heart of Change. Harvard Bus. School, 2002.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.