Pang-alay ritual pottery in ancient Philippines - Ronquillo, Wilfredo P.; De La Torre, Amalia A.; Valdes, Cynthia Ongpin; Dizon, Eusebio Z.; Bautista, Edwin R.; Bautista, Angel P.; Trenas, Jose Maria P.; Cuevas, Nida T.; Barretto, Grace; Gatbonton, Esperanza Bunag (Ayala Foundation, Inc. in cooperation with the Oriental Ceramic Society of the Philippines, 2003)