The ERIC (Education Resources Information Center) database is sponsored by the U.S. Department of Education to provide extensive access to educational-related literature.
Index to periodical articles on all areas of business including marketing. Many articles are full text and you can limit your search to scholarly articles.
The OED is widely regarded as the most significant dictionary of the English language, offering the meaning, history, and pronunciation of more than 600,000 words —past and present— from across the English-speaking world.