"Her purpose here is to discuss and illustrate the four types of brain waves--beta, alpha, theta, and delta--with emphasis on what they do, how they work together, and whether we can use their power."--Booklist.
"Her purpose here is to discuss and illustrate the four types of brain waves--beta, alpha, theta, and delta--with emphasis on what they do, how they work together, and whether we can use their power."--Booklist.
