1 periodical author. Title [J] Title, year of publication, volume (issue): author of 2 monographs on the beginning and end pages. Title [M]. Version (first edition not recorded). Place of publication: publisher, year of publication. Start and end page 3 Collect authors. Title [C]. //editor. Collection name. Title of the 5th year patent document [P]. Country, patent document type, patent number. Publication date 6 standard number, standard name [S] 7 newspaper author. Title. Name of newspaper, date of publication (edition) 8 Report author. Title [R]. Save location: author of ninth grade electronic document. Title [Electronic document and carrier type identification]. Document date II. Document type and its identification 1. According to GB3469, ① periodical [J] ② monograph [M] ③ paper [[CD] ④ dissertation [D] ⑤ patent [P] ⑤ standard [S] ⑦ newspaper [N] ⑧ technical report [R] 2. For example, the carrier type of an electronic document is identified by two letters.