(from Introduction) For four years last century I had the rare privilege of taking part in a series of liturgical consultations organized by the Lutheran World Federation. I say "rare", because it is not often that a Roman Catholic becomes member of an international study group of Lutherans and, to my gratification, declared by the group an honorary Lutheran! By coincidence or perhaps providence Martin Luther and I were born on the same day. During those memorable years I made lasting friendship with Lutheran scholars like Gordon Lathrop and Anita S. Stauffer. Friendship meant dialogue, and dialogue with them richly endowed me with liturgical knowledge. Thanks to my Lutheran connection, the World Council of Churches paired Lathrop and me in a number of conferences on Christian worship.
Chupungco, Anscar J., "Inculturation of Worship: Forty Years of Progress and Tradition" (2003). Institute of Liturgical Studies Occasional Papers. 5.