APA

SOARS JOHN, . (1987). HEADWAY WORKBOOK UPPER-INTERMEDIATE. : .

Chicago

SOARS JOHN, . 1987. HEADWAY WORKBOOK UPPER-INTERMEDIATE. : .

Harvard

SOARS JOHN, . (1987). HEADWAY WORKBOOK UPPER-INTERMEDIATE. : .

MLA

SOARS JOHN, . HEADWAY WORKBOOK UPPER-INTERMEDIATE. : . 1987.