DeFrancis, John (1989): Visible Speech. The Diverse Oneness of Writing Systems /// Visible speech. The diverse oneness of writing systems. Honolulu: Univ. of Hawaii Pr.
Hincha, Xieyan (2003): Ist Hanyu Pinyin eine Schrift? In: CHUN - Chinesischunterricht 18, S. 117–129.
Li, Xiuqin (1991): Evolution de l'écriture Chinoise. Paris: Editions You Feng.