Port statistics :  selection, collection and presentation of port information and statistics : manual / 

 - New York :  United Nations,  1971. 
 - iii, 40 p. ;  28 cm. 
 - United Nations. Document. TD/B/C.4/79/Rev.1 .
<br/><br/> 'United Nations publication. Sales no.: E.72.II.D.1.' 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Harbors--Statistics.