(1) developing a new technique for obtaining nonperturbative information about a quantum field theory by expanding the Green`s functions as series in powers of D, the dimension of space-time, (2) discovering a new and promising kind of continuum field-theoretic perturbation expansion called the delta expansion, (3) inventing methods for finding the analytical solution of operator differential equations, (4) studying strong-coupling and lattice approximations in quantum field theory, (5) originating the field of large-order behavior of perturbation theory, and (6) miscellaneous research projects