A family of Microsoft relational database management systems designed for ease of use.
Hmm that's strange since the sort order was working when I last looked. It may have to wait until I return from vacation before I can look at it.
As far as using a Combo to select the month, you should be able to do that. I would create a table for each period. Like I said, the period should include the year as well. Will there be a core for every calendar month? if not, all the more reason to use a table.