op. cit.
adverb publishing formal specialized uk/ˌɒp ˈsɪt/ us/ˌɑːp ˈsɪt/
（用于避免重复前文提到的书或文章的细节）同上，同前文所引
used by writers to avoid repeating the details of a book or article that has already been referred to, when all the details other than the page number are the same
Johnson (op. cit., page 53) calls this phenomenon "the principle of minimal effort". 约翰逊（同上，第53页）把这种现象称为“最小努力原则”。
Compare: loc. cit.