00268nam a2200109Ia 4500008004000000082001500040100001600055245002200071260004300093300001200136650001000148210210b1962   xxu||||| |||| 00| 0 eng d  a668.4 PENP  aPENN (W S).  aP V C technology.  aLondon.bMaclaren & Sons., Ltd.,c1962  axiv,385  aPVC