000 00398nam a2200121Ia 4500
100 _aWorld Health Organization
020 _a92-4-154496-1
942 _cBK
245 _aDetermination of airborne fibre number concentrations : a recommended method, by phase - contrast optical microscopy (membrane filter method)
260 _aauth., Geneva
_c1997
082 _a614.71 WHO
300 _aviii,53p figs.
999 _c35817
_d35817