Bibawy, Nabil A. <br/><br/>
An improved method for preparing gravimetric standard gas mixtures of helium-4 in nitrogen / 
by Nabil A. Bibawy and David E. Emerson. 
 - Washington, DC :  United States Dept. of the Interior, Bureau of Mines,  1990. 
 - 7 p. :  ill. 
 - Report of investigations ;  9312 .
 - Report of investigations (United States. Bureau of Mines);  9312.    .
<br/><br/><label>LCCN: </label>91045114     
<br/><br/><label>Subjects--Topical Terms: </label><br/>Gases.<br/>Mixing.<br/>Helium.<br/>Nitrogen.