What has the author Charles Harper written?

You're likely thinking of Charles Harper Webb, an American illustrator known for his bold, colorful, and graphic style.

He is best known for his iconic posters depicting birds of the National Audubon Society, but he has also created works for:

* The New York Times

* The New Yorker

* Time Magazine

* The Smithsonian Institution

* The United States Postal Service

* Numerous children's books

Some of his notable books include:

* Birds of the National Audubon Society

* The Bird Book

* The Bird Book for Kids

* The Animal Book

If you meant another Charles Harper, please provide more information.