ISBN 9781580375238 books & textbook
Mark Twain - Simple Machines, Grades 6 - 12 (Expanding Science Skills Series)
Beaver Ph.D., John B. Sandall Ed.D., Barbara R.
Mark Twain Media /2010-01-04 Paperback / 80 Pages
isbn-10: 1580375235 / isbn-13: 9781580375238
