Lehrbuch; Arbeitsbuch; Course book; Textbook; Workbook; Übungsbuch; Introductions (to linguistics) ; Nachschlagewerke; Reference books ; Second language acquisition (language teaching) ; Zweitspracherwerb (Unterricht) ; Foreign language teaching ; Erstspracherwerb; First language acquisition; Ontogenese; Language acquisition ; Second language acquisition (psycholing.) ; Transfer (second language acquisition) ; Transfer (Zweitspracherwerb) ; Cross-linguistic influence (second language acquisition) ; Interference (second language acquisition)