एपीए उद्धरण

Mark Griffiths. (2014). Essential tests for IELTS. Tổng hợp.

शिकागो स्टाइल उद्धरण

Mark Griffiths. Essential Tests for IELTS. Tổng hợp, 2014.

एमएलए उद्धरण

Mark Griffiths. Essential Tests for IELTS. Tổng hợp, 2014.