additional works 2015-03-28 EXTRA 31 not scanned separately yet https://www.doujinshi.org/book/1159108/Extra-31/ but included in https://e-hentai.org/g/1239380/3a4ab2dc7e/ . Despite being the first it is included after bonus? Not translated yet
Other 2017-12-31 Extra48 not scanned yet has sample show some SAO content https://www.doujinshi.org/book/1101038/Extra-48/ 2018-08-12 Extra 54 https://e-hentai.org/g/1427455/40c50be36d/ some rough sketches. nothing to translate