Collins. (2013). Work on your grammar (Advanced C1): Over 200 exercises to improve your English grammar. Tổng hợp.
Chicago Style citaatCollins. Work On Your Grammar (Advanced C1): Over 200 Exercises to Improve Your English Grammar. Tổng hợp, 2013.
MLA citatieCollins. Work On Your Grammar (Advanced C1): Over 200 Exercises to Improve Your English Grammar. Tổng hợp, 2013.
Let op: Deze citaties zijn niet altijd 100% accuraat.