The Avesta Codex K5, University Library of Coprnhagen First Part: The Introduction to the Yasna, Yasna I-20, and an Appendix ( Tracing of Folios 70-77 of K5 and the Manuscript K5 b 20 + 253 p 30 x 23 1978 گنجینۀ دستنویسهای پهلوی و پژوهشهای ایرانی