Journal of research of the National Bureau of Standards :   1978 / 
United States. National Bureau of Standards. 
 - Washington, D.C.:  U.S. Govt. Print. Off. 
 - v. 
<br/><br/><label>ISSN: </label>0091-0635 
<br/><br/><label>Universal Decimal Class. No.: </label>6:386.6(05)