Zobel de Ayala, Fernando2020-07-291955Zobel de Ayala, Fernando. 1955. A calligraphic duel. Harvard Library Bulletin IX (1), Winter 1955: 46-60.0017-8136https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37363545en-USJournal Article2020-07-29