1. Optimal Trajectories and the Accessory Minimum Problem;Bell;Aeronaut. Q.,1965
2. “Lectures on the Calculus of Variations”;Bliss,1946
3. “Applied Optimal Control”;Bryson,1969
4. Optimal Powered Arcs in an Inverse Square Law Field;Lawden;J. Am. Rocket Soc.,1961
5. Optimal Intermediate-Thrust Arcs in a Gravitational Field;Lawden;Astronautica Acta,1962