El círculo

The United States grew rapidly from the time of the Louisiana Purchase to the building of the Transcontinental Railroad. All of this expansion came at the expense of Native American populations that had either lived in the region for centuries or been forced there from ancestral homes in the East. Tribes memorably fought on their own and together in an doomed effort to retain the land and a lifestyle that had long sustained their families. This book outlines some of the major conflicts of the Westward Expansion, and of the treaties and were signed, and often broken, by representatives of the...

Este poeta, premio Nobel 1977, sabía que los niños comprenden a veces más y mejor que lo que los adultos suponen, y que únicamente hay que ofrecerles un mundo que puedan compartir.

This book is a comprehensive, practical presentation of the principles of behavior modification and guidelines for their application. It teaches forms of behavior modification ranging from helping children learn necessary life skills to training pets, to solving personal behavior problems.

This Title Explains What An Ecosystem Is And How The Plants And Animals Within An Ecosystem Rely On And Effect Its Existence. Different Types Of Ecosystems Are Described, As Well As The Food Webs Within Them. How Some Changes To An Ecosystem Can Be Good And How Some Harmful Changes Can Destroy Them. Teaches Students What An Important Role They Can Play In Keeping These Intricate Ecosystems Alive.