An introduction to linear difference equations / by Paul M. Batchelder ... published with the coöperation of the National research council. Batchelder, Paul M. (Paul Mason), 1886- Difference equations. QA431 .B3 517.38 BAI Cambridge, Mass. : The Harvard University Press, 1927. 1927. 1927 Text vii, [1], 209 p. : eng