Dear Tom,

The particular selections chosen would have varied a lot, depending on which breviary or lectionary of saints was being used. If you're just interested in the *Dominican* lessons for Dominic's office, finding those should be pretty easy because the OP had one official breviary and kept a tight rein on revisions. I'm at home today and don't have the reference at hand, but could look it up for you later this week when I'm in the library,

The official Franciscan and Roman version(s) of the lessons should also be relatively few in number and easy to find. English secular breviaries, on the other hand, tended to shorten and rewrite the lessons quite freely, so their lessons can vary enormously even if they all originally stemmed from the same text. And the surviving English monastic sources are even more unpredictable (though they're perhaps unlikely to have lessons for Dominic at all).  I know a lot less about lectionaries of saints in other parts of Europe, but suspect that other regions and locales probably had their own textual traditions as well. 

For whatever it's worth . . .

Sherry Reames (Professor Emerita, University of Wisconsin-Madison)