Academic research has identified that business/marketing journals tend to draw on knowledge from a diverse set of disciplines. However, there has been limited examination of the source of these ideas in terms of types of materials (journals, books, conferences, business/popular press and other sources) or whether the use of these sources has changed over time. This paper examines these issues and found that within the three leading marketing journals (JM, JMR, JCR), the citation of journal articles has generally increased over time and the citation of nonjournal sources (i.e., journals, books, conferences, business/popular press and other sources), have generally decreased. There are, however, differences in the specific citation behaviour in the three journals and thus the citation of materials may be journal specific.<br /