I am looking for a grammar book or series of grammar books for German that match the following criteria:
- the book or books must be in German, i.e. all grammar rules and instructions must be in German (not English, Spanish, French, ...);
- content should be organised in chapters that first explain a set of grammar rules and then provide a number of exercises that apply these rules;
- there must be an answer key (the answer key may be a separate volume);
- the book must be appropriate for self study (the presence of an answer key is not sufficient; some books of this type are intended for teachers of German).
I am looking for books for the levels A2 - B2. The first three criteria may be easy to fulfil, but the last criterion is essential and it may not be obvious whether a book matches this criterion just by looking at the book cover in an online bookshop. Answers that are based on personal experience using such books would be especially appreciated. Since there are several German publishers that specialise in language books, there should be several such grammar books.