Moving the earth : the workbook of excavation / Nichols, Herbert L., Illus. by Helen Schwagerman. Nichols, Herbert L. (Herbert Lownds), 1908- Earthwork. Earthmoving machinery. Excavation. TA735 .N52 1962 624.152 NIM Includes index. New Delhi : Galgotia Publishing House, c1962. c1962. 1962 Text xxxi, various pagins. : eng