“Forthcoming” can stand in place of the date in references to Extension publications that have been titled and numbered but have not been released yet. (Check with Lagene Taylor; generally this means near the end of, or past, the editing stage.) Publications that are simply planned or in process but not yet through the peer review stage cannot be cited.
Example: Butler, G. Forthcoming. How to Win Everything. University of Belize Extension Publication 0001.