About “Kiev Missal”
The Kiev Missal is a Glagolitic Old Church Slavonic canon manuscript that contains parts of the Roman-rite liturgy. It consists of seven parchment folios and is considered the oldest and most archaic Old Church Slavonic manuscript. It is dated to no later than the latter half of the 10th century. The manuscript was produced in a small format, making it easy to carry, and was likely intended for use by missionaries who needed a portable liturgical text. (Summary adapted from Wikipedia, CC BY-SA 4.0.)
Some summaries adapted from Wikipedia, CC BY-SA 4.0.