00421nam a2200145 a 450000500170000002000150001708200160003210000170004824500910006526000330015630000170018949000280020663000270023470000140026120251203091959.0  a0070990069  a515.35bAYR  aAyres, Frank  aTheory and proplems of differential equations in SI metric units, Frank Ayres Jr. leng  aSingapore, McGraw-Hillc1972  a295p.c26 cm  aSchaum's outline series  aDifferential equations  aAult, JC.