Whitcher, Charles E. <br/><br/>
Control of occupational exposure to (N2O) in the dental operatory / 
by Charles E. Whitcher 
 - Washington, D.C. :  United States Department  of Interior,  1977 
 - 42 p. ;  24 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Industrial hygiene<br/>Industrial safety
<br/><br/><label>Dewey Class. No.: </label>363.11