Common types of letters of recommendation are:
1, monograph [M], collection of essays [C], newspaper articles [N], journal articles [J], dissertations [D], reports [R], standards [S], patents [P], and documents deposited in papers [a];
2. Electronic file types: database [DB], computer [CP], electronic bulletin [EB];
3. Carrier types of electronic documents: Internet [OL], compact disc [CD], magnetic tape [MT] and disk [DK].
Description format of references
1, author of the journal. Title [J] Name of publication, year of publication, volume (issue): page numbers.
2. Monograph author. Title [m]. Version (first edition not recorded). Place of publication: publisher, year of publication: page number.
3. Author, title [c] and editing procedure, name procedure, place of publication: publisher, year of publication: start and end pages.
4. Author of the paper. Title [D] Save the location. Save unit. Year.
5. Title of the patent document [P]. Country. Types of patent documents. Patent number. publication date
6. Standard number. Standard name
7. newspaper author. Title. Newspaper name. Publication date (version)
8. Author of the report. Title [R]. Save the location and year.
9. Author of electronic document. Title [Identification of electronic documents and carrier types]. The source and date of the document.