How do I create a method to return the results of a group by in LINQ to sql such as the one below:

internal SomeTypeIDontKnow GetDivisionsList(string year)
{
    var divisions =  from p in db.cm_SDPs
                          where p.acad_period == year
                          group p by new
                          {
                              p.Division
                          } into g
                          select new
                          {
                              g.Key.Division
                          };
    return divisions;
}

I can't seem to define a correct return type. I think it is because it's an anonymous type but haven't got my head around it yet. Do I need to convert it to a list or something?

The results would just be used for filling a combo box.