Life's Imponderables: The Answers to Civilization's Most Perplexing Questions : Why Do Clocks Run Clockwise? When Do Fish Sleep? Why Do Dogs Have Wet Noses? (Life's Imponderables)

How Does Aspirin Find a Headache?: An Imponderables Book

Why Do Dogs Have Wet Noses? and Other Imponderables of Everyday Life

When Do Fish Sleep: And Other Imponderables of Everyday Life

A World of Imponderables: The Answers to Life's Most Mystifying Questions (Imponderables Series)

Why Do Clocks Run Clockwise? and Other Imponderables: Mysteries of Everyday Life Explained

What Are Hyenas Laughing At, Anyway? An Imponderables Book

When Do Fish Sleep? And Other Imponderables of Everyday Life

How Do Astronauts Scratch an Itch: An Imponderables Book (Imponderables Book)

When Did Wild Poodles Roam the Earth?: An Imponderables Book