Title:  The maximum principle in the theory of optimal processes of control (with discussion) 
 Authors:  V. G. Boltyanski, R. V. Gamkrelidze, E. F. Mishchenko, L. S. Pontryagin 
 Journal title:  Automatic and Remote Control 
 Year:  1960 
 Volume:  1 
 Pages:  454–459 

