WOW! : the wonders of wetlands / produced through a partnership between Environmental Concern, Inc. and The Watercourse ; principal authors: background materials for teachers, Alan S. Kesselheim, original version of WOW!, Britt Eckhardt Slattery, illustrations (unless otherwise noted), Britt Eckhardt Slattery, activity section edited and reformatted by Susan H. Higgins and Mark R. Schilling