The Illustrated Science And Invention Encyclopedia Set of 21 Volumes
H.S. Stuttman Publishers
Excellent homeschool source.
One (1) 1983 Science Supplement added as gift!
Republished in the United States in 1974 by H.S. Stuttman Publishers in Westport, Connecticut, in 21 volumes. Before 1974 originally published in parts in the United Kingdom under the title How It Works, by Marshall Cavendish Limited.