===Manuscripts and editions===
The authorities for this rite are chiefly in manuscript, the printed editions being very few
[[as of 1912 ]]. Few of the manuscripts, except some lectionaries in the British Museum, were written before the fifteenth century, and most, whether Chaldean or Nestorian, are of the seventeenth and eighteenth. The books in use are:
*[[Takhsa]], a priest's book, containing the Eucharistic service ([[Qurbana]] or [[Qudasha]]) in its three forms, with the administration of other sacraments, and various occasional prayers and blessings. It is nearly the [[Euchologion]] of the Greeks (see [[Rite of Constantinople]]).