Lewis, D C <br/><br/>
Inequalities for Complex Linear Differential Systems of the Second Order.  [electronic resource] 

 -  Proceedings of the National Academy of Sciences of the United States of America  Jan 1952 
 - 63-6 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>0027-8424 
<br/><br/><label>Standard No.: </label>10.1073/pnas.38.1.63  doi