APA

Gerngross G., Puchta H., .Playway 4 Pupils Book. Stuttgart: .

Chicago

Gerngross Günter, Puchta Herbert, .Playway 4 Pupils Book. Stuttgart: .

Harvard

Gerngross G., Puchta H., .Playway 4 Pupils Book. Stuttgart: .

MLA

Gerngross Günter, Puchta Herbert, .Stuttgart: . .