In 1972, Serbo-Croatian was the official, unified pluricentric language of the Socialist Federal Republic of Yugoslavia. The textbook reflects this linguistic unity. It teaches the core structural similarities while acknowledging regional vocabulary variations (such as the differences between the Western/Croatian vlak and Eastern/Serbian voz for "train"). For historians and sociolinguists, the book is a time capsule of how the language was standardized and presented to Western Europeans during the Cold War. 2. The Pedagogy of Tonka Nikolić