000 003250000a22001330004500
245 _aAppropriate technologies for developing countries
100 _aEckaus, R.S.
260 _aWashington
_bNAS
_c1977
300 _axiii, 140p. : ill.
020 _a0309026024
080 _a62.001.8
_bE3
041 _aEN
942 _cBK
999 _c109889
_d109889