Cartan, Elie, 1869-1951.  Cartan, Elie, 1869-1951. <br/><br/>
Lecons sur les invariants integraux. 

 - Paris :  Hermann,  [1971] 
<br/><br/> First published in 1922. 
<br/><br/>Bibliography: p. [205]-206. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Differential equations.<br/>Celestial mechanics.