Economic Commission for Europe   Annual report 18 April 1991-15 April 1992. 

 - New  York U.N.        1992 
 - Supplement no.12 .
<br/><br/><label>Standard No.: </label>171837 
<br/><br/><label>Source: </label> Reference Collections 
<br/><br/><label>Dewey Class. No.: </label>"V1N45,93:3.N92 - N91r, M2-12/UN"