00251nam a22000977a 450000500170000000800410001704000130005808200230007124500400009426000190013420180704120631.0180704b        xxu||||| |||| 00| 0 eng d  cPK-LaUMT  aMJC 050.9397bNAT-  aNational Geographic (Vol.169 no.3)/  a[ ]b[ ]c1986