Robert K. Ullman

title	ISBN-13	year of publica- tion	other author(s)
Exploring Light and Color	978-0-07-134821-8	1999	Heidi Gold-Dworkin · K. Almadingen
Fun with Mixing and Chemistry	978-0-07-134825-6	2000	Heidi Gold-Dworkin
Fun With Water and Bubbles	978-0-07-134823-2	1999	"
Learning About the Changing Seasons	978-0-07-134822-5	2000	"
Learning About the Way Things Move	978-0-07-134824-9	2000	"
The Big Book of Cool Inventions: Tons of Inventions, Experiments, and Mind Bending Games	978-0-07-135208-6	2000	Margaret Kenda · William Kenda