download citations

When I download citations from publisher websites (e.g.
Cambridge UP)
the date field is empty (year is OK). Does anybody know what
I'm doing
wrong?

--
Robert Wolfe
Professor
School of Policy Studies, Queen's University, Kingston,
Canada K7L 3N6
Office (613) 533-6689 Home (613) 545-3427 Cell (613)
539-7545
Robert.Wolfequeensu.ca
http://www.queensu.ca/sps/people/faculty/wolfer/index.p
hp