Lasso, O. d., & Blachly, A. (1999). Motets for the Christmas season: For mixed voices in five parts. New York : Boston: Gaudia Music and Arts ; sole agent, ECS Pub..

Lasso, Orlando di, and Alexander Blachly. Motets for the Christmas Season: For Mixed Voices in Five Parts. New York : Boston: Gaudia Music and Arts ; sole agent, ECS Pub., 1999.

Lasso, Orlando di, and Alexander Blachly. Motets for the Christmas Season: For Mixed Voices in Five Parts. New York : Boston: Gaudia Music and Arts ; sole agent, ECS Pub., 1999.