Here are the booklets for this Sunday:
Vespers booklet: 29th Sunday in Ordinary Time (Year C)
Mass booklet: 29th Sunday in Ordinary Time
Two of the chants in the Mass booklet (offertory Meditabor and communion Domine Dominus noster) feature low B-flats. These present an interesting theoretical/editorial conundrum. To learn more, you can look at this discussion on Musicologie Médiévale.
I have also begun to upload certain important historical Dominican chant books on this page. I have formatted these with proper logical pagination to make them easier to navigate.