The Linear Nonconvex Generalized Gradient and Lagrange Multipliers. - Jay S. Treiman (SIAM J. Optim., 1995)

A linear extremal principle. - Jay S. Treiman (CDC, 2002)

An Extended Extremal Principle with Applications to Multiobjective Optimization. - Boris S. Mordukhovich; Jay S. Treiman; Qiji J. Zhu (SIAM J. Optim., 2003)