aasjournal.bst sorts by appearance in text

[augustfly]

aasjournal.bst was changed (in 2016) to sort entries with the same author/year by appearance in the text. in other words, Abbott et al 2017a, Abbott et al 2017b, Abbott et al 2017c are given the "a,b,c" designations based on when they are used in the manuscript not when they were published.

as our formal recommendations do not specify how the "a/b/c" designations should be applied when preparing a manuscript, this behavior is not problematic as is. It may produce unexpected behavior if the author's expected order is by publication date (volume/issue/page) or to be sorted by title like some journals do.

concerns/frustrations/comments on this "feature" are welcome.