000 00264nam a2200109Ia 4500
008 220201s1971 xx 000 0 eng d
100 _aSubhash C, Saxena
245 0 _aTunnel engineering
260 _bDelhi:Dhanpat rai & sons
_c1971
300 _a175
942 _2ddc
999 _c79091
_d79091