Simple economics and book-keeping for fish farmeres 
/ prepared by Colin Williams 
. - Roma  : Food and Agriculture Organization of the Unietd Nations, 1983
. - V-52 p.  ; 30 cm 
 - FAO fisheries circular  763 .
<br/><br/><label>Source: </label> don 
<br/><br/><label>Universal Decimal Class. No.: </label>639.3