La Tierra (Earth)

This complete Spanish translation of the highly acclaimed Isaac Asimov's 21st Century Library of the Universe is ideal for students still developing their English-language skills.

This complete Spanish translation of the highly acclaimed Isaac Asimov's 21st Century Library of the Universe is ideal for students still developing their English-language skills.

Describes The Physical Characteristics, Behavior, And Metamorphosis Of Insects, And Insects In Your Garden, Backyard And In Your Home.

Examines the apparent connection between birds and dinosaurs by comparing fossils, dinosaur bones, and modern birds.

Nuestro mundo, with Tu mundo, is a complete, two-level Spanish program for native Spanish speakers, providing focused treatment of Spanish-speaking peoples, including language, literature, culture, and history.

La teoría de conjuntos es una rama de las matemáticas, y cuya dedicación de este capítulo, es gracias al matemático, Ferdinand Ludwing Philipp Cantor, quien es considerado el padre de la Teoría de Conjuntos, debido a ello, es que, en el año 1874, salió su primer trabajo revolucionario, con respecto a la teoría de conjuntos.