@Article{FR75a,
  author = 	 { Robert W. Floyd and Ronald L. Rivest },
  title = 	 { Expected time bounds for selection },
  pages =        { 165--172 },
  url =          { http://doi.acm.org/10.1145/360680.360691 },
  doi =          { 10.1145/360680.360691 },
  acm =          { 94099 },                  
  journal = 	 { Communications of the ACM },
  OPTyear = 	 { 1975 },
  OPTmonth = 	 { March },
  date =         { 1975-03 },                  
  volume = 	 { 18 },
  number = 	 { 3 },
  publisher =    { ACM },
  acmid =        { 360691 },
  abstract =     { 
                   A new selection algorithm is presented which is
                   shown to be very efficient on the average, both
                   theoretically and practically.   The number of comparisons
                   used to select the $i$th smallest of $n$ numbers is
                   $ n + \min(i,n-i) + o(n) $.  A lower bound within 9
                   percent of the above formula is also derived.
                 }                  
}