Issues #14-15 were part of the 1982 "Crisis on Earth-Prime" crossover with the Justice League of America (that year's annual JLA and JSA meeting) and was included in the Crisis on Multiple Earths Vol. 6 collected edition.
Issues#50-60 were either CoIE cross-over issues of were continuations of stories begun during then (with issue #60 showing the differences in the "before" and "after" membership).