000 00322nam a2200133Ia 4500
008 210901s1971 xx 000 0 eng d
082 _a629.83 POR
100 _aPorter, Arthur
245 0 _aIntroduction to servomechanisms
260 _aLondon
_bMethuen
_c1971
300 _a176
650 _aAgriculture
942 _2ddc
_cBK
999 _c7964
_d7964