@book {4887, title = {The feast of the nativity of our Lord in the Chaldean and Malabar liturgical year: a study of the Sources}, series = {Oriental Institute of Religious Studies}, number = {127}, year = {1989}, publisher = {Oriental Institute of religious studies}, organization = {Oriental Institute of religious studies}, address = {Kottayam}, keywords = {Liturgy}, author = {Peter Kuruthukulangara} }