Your statement is correct, but not complete. In addition to the Lectionary and the Missal there is always a "Book of Gospels" present that is proclaimed within the Liturgy of the Word.
Note that the Liturgy of the Mass predates the Bible. One of the driving forces to produce a Bible was the need for clarity in which readings were recognized as being acceptable for reading during the Mass.
Peace be with you.
What's notable in the concept of a "recently approved vernacular Lectionary". The Lectionary published by the USCCB is what's generally used at Mass the US and it is not a Bible.