The Major Tasks of Marketing Management, Journal of Marketing
Marketers engage in a variety of tasks which are not carefully distinguished in the literature but which are radically different in the problems they pose. Eight different marketing tasks can be distinguished, each arising out of a unique state of demand. Depending upon whether demand is negative, nonexistent, latent, irregular, faltering, full, overfull, or unwholesome, the marketer finds himself facing a unique challenge to his craft and his concepts.
Kotler, Philip. 1973. The Major Tasks of Marketing Management. Journal of Marketing. 37(4): 42-49.