Lehrbuch; Arbeitsbuch; Course book; Textbook; Workbook; Übungsbuch; Introductions (to linguistics) ; History of linguistics (19th century) ; History of linguistics (20th century) ; DaF; Deutsch als Zweitsprache; German as a second language; DaZ; German as a foreign language ; Pronunciation (standardization of) ; Standardaussprache; Orthoepy ; Rechtschreibung; Spelling; Orthography ; Phonetics ; Phonemik; Phonology ; German