Advanced grammar in use : a self-study reference and practice book for advanced learners of English ; with answers
3
English grammar in use : a self-study reference and practice book for intermediate learners of English ; mit Kurzgrammatik für deutschsprachige Lernende ; with answers
4
MyGrammarLab advanced C1/C2 : with key
5
Practical English usage : [complete topic-by-topic grammar : guide to over 250 vocabulary problems]
Michael Swan
6
Oxford advanced learner's dictionary of current English