CIC/1917, can. 0851
§ 2. Ubi vero necessitas urgeat nec sacerdos diversi ritus adsit, licet sacerdoti orientali qui fermentato utitur, ministrare Eucharistiam in azymo, vicissim latino aut orientali qui utitur azymo, ministrare in fermentato; at suum quisque ritum ministrandi servare debet."
Bibliography
CIC/1917, can. 851, in: www.jgray.org (Last access: 16.10.2017).
Codex Iuris Senior, can. 851, in: www.catho.org (Last access: 16.10.2017).
GASPARRI, Pietro (Hg.), Codex Iuris Canonici Pii X Pontificis Maximi iussu
digestus, Benedicti Papae XV auctoritate promulgatus, Rom 1917, S. 244,
can. 851, in: www.archive.org (Last access: 16.10.2017).