EN
This article is a general introduction of liturgical books, with a special focus on the Gradual, which were funded by primate Jan Łaski ca. 1520 for the church in Łask. An exact number of the books is unknown, presumably there were nine of them. Seven books have been preserved until nowadays: two volumes of the Gradual, two volumes of the Antiphonary, two Psalters and one Cantatorium. Actually, the Graduals and one of the Psalters remain in the State Archive in Łódź.