this is my first entry, so please be patient – and many thanks in advance for that.

I am writing an article on a historical subject, and would like to include the year of first publication in addition to the year of the publication I use. For example: Locke (1690/2008)
If I simply write "1690/2008" into my BibTeX file, nothing changes. All I get in my document is "Locke (2008)".
Any ideas how to fix this?