00473nam a22001697a 450000500170000000800410001702000190005804000130007708200180009010000250010824500860013325000120021926000390023130000110027065000110028165000110029220250625121322.0250625b        |||||||| |||| 00| 0 eng d  a97806320498999  cPK-LaUMT  a617.75bELK-C  aElkington, Andrew R.  aClinical optics /cby Andrew R. Elkington, Helena J. Frank and Michael J. Greaney  a3rd ed.  aOxford :bBlackwell Science,c1999  a254 p.  aLenses  aOptics