La optimización mecánica en el medio acuático

In this biographical book, young readers will learn about the brave life of Harriet Tubman. Readers will discover how Tubman bravely escaped from her life as a slave to cross the Mason-Dixon line into freedom and how she helped hundreds of other slaves into freedom through the Underground Railroad with the help of abolitionists. The vivid images, stunning facts, and supportive text work in conjunction with the helpful glossary, index, and timeline of Tubman's life to give readers an engaging experience as they move from cover to cover. This book has been translated into Spanish.

A simple biography of the naturalist who founded the Sierra Club and was influential in establishing the national park system.

Venerado y vilipendiado a un tiempo, Lobachevski se cierne imponente sobre la matemática del siglo XIX. Al igual que sucede a la mayoría de los mitos, el Lobachevski real está oculto por capas de negligencia y desconocimiento. Su fantástica obra, argumentaban muchos, no era otra cosa que herejía matemática, una senda falsa. Lobachevski es una personalidad abrumadora, un soñador empedernido, un hacedor de mundos imposibles pero reales. Lobachevski es, para muchos, una persona desconocida. Este libro cuenta la historia de un hombre sencillo, pero sagaz, obstinado y profundo desde el...

The Spanish-language edition of Wilma Unlimited. Before Wilma was five years old, polio had paralyzed her left leg. Everyone said she would never walk again. But Wilma refused to believe it. Not only would she walk again, she vowed, she'd run. And she did run--all the way to the Olympics, where she became the first American woman to earn three gold medals in a single olympiad.