Bellman Richard <br/><br/>
Perturbation techniques in mathematics, physics, a 
Bellman Richard 
 -  1964 
 - Athena Series Selected Topics in Mathematics. Ed by Edwin Hewitt,1964 .
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Equations
<br/><br/><label>Dewey Class. No.: </label>B33, K4