Procter, P., Ilson, R., & Ayto, J. (1978). Longman dictionary of contemporary English / [editor-in-chief Paul Procter, managing editor Robert F. Ilson, senior editor John Ayto]. Longman.
Chicago Style (17th ed.) CitationProcter, Paul, Robert Ilson, and John Ayto. Longman Dictionary of Contemporary English / [editor-in-chief Paul Procter, Managing Editor Robert F. Ilson, Senior Editor John Ayto]. Harlow (etc.): Longman, 1978.
MLA (9th ed.) CitationProcter, Paul, et al. Longman Dictionary of Contemporary English / [editor-in-chief Paul Procter, Managing Editor Robert F. Ilson, Senior Editor John Ayto]. Longman, 1978.
Warning: These citations may not always be 100% accurate.