Proposals for revision of the 1928 BCP were first published by the Standing Liturgical Commission in a series of Prayer Book Studies, the first of which was published in 1950. When trial use of a revision of the eucharistic rite was authorized by the 1967 General Convention, pew copies were printed in a book titled The Liturgy of the Lord's Supper. A revision of the eucharistic rite, a new eucharistic lectionary, and revisions of the Daily Office, the pastoral offices, and the ordination rites were authorized for trial use by the 1970 General Convention and published in Services for Trial Use. It was known as the "Green Book" because of its green cover. Additional changes authorized in 1973 were published in Authorized Services 1973, known as the "Zebra Book" because of its striped cover. Further revisions were incorporated in a complete Prayer Book, The Draft Proposed Book of Common Prayer, which was essentially a workbook for the use of bishops and deputies to the 1976 General Convention. The book authorized by that convention was published as the Proposed Book of Common Prayer. That Prayer Book was ratified by the 1979 General Convention, making it the authorized BCP of the Episcopal Church.