by Bahill, A.T., Alford, M., Bharathan, K., Clymer, J.R., Dean, D.L., Duke, J., Hill, G., LaBudde, E.V., Taipale, E.J., Wymore, A.W.
Published in IEEE transactions on systems, man and cybernetics. Part C, Applications and reviews (01.02.1998)

by Sandhu, G.S., LaBudde, E.V.
Published in IEEE transactions on aerospace and electronic systems (01.01.1978)