HSK 4 Standard Course Workbook : Workbook (下).

MLA

李兵 - Li Bing. Hsk 4 Standard Course Workbook : Workbook (下). 北京: 北京语言大学电子音像出版社 Beijing Language and Culture University Electronic and Audiovisual Press, 2015.

APA

李兵 - Li Bing, 李. - Li Bing. (2015). HSK 4 Standard Course Workbook : Workbook (下). 北京: 北京语言大学电子音像出版社 Beijing Language and Culture University Electronic and Audiovisual Press.

Chicago

李兵 - Li Bing, HSK 4 Standard Course Workbook: Workbook (下). 北京: 北京语言大学电子音像出版社 Beijing Language and Culture University Electronic and Audiovisual Press, 2015.