Volume 15 is Supplement I; it contains additional biographies as well as topical essays on non-Western scientific traditions. Volume 16 is the general index. A 2-volume Supplement II with additional biographies was published in 1990.
The supplement series consists of Volume 15, which contains additional biographical information and essays about non-Western scientific practices and traditions. The main reference work concludes with Volume 16, a comprehensive index. Two volumes of Supplement II were published in 1990, featuring extra biographies.