Updegraff, M <br/><br/>
ON THE MEASUREMENT OF TIME.  [electronic resource] 

 -  Science (New York, N.Y.)  Feb 1902 
 - 216-20 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>0036-8075 
<br/><br/><label>Standard No.: </label>10.1126/science.15.371.216  doi