00511cam a2200169 4500 622944130 TxAuBib |||||||||||||||||||||||||||||||||||eng|u 9780516216805 0516216805 TxAuBib Fowler Allen. Simple Machines. U. S.A : Grolier Publishing. Describes and compares the four kinds of simple machines levers, pulleys, wheels, and ramps. TXHAP