D. Willett

Belowground pumped storage

D. Willett, 1977 .

A linear generalization of Gronwall’s inequality

D. Willett, D. Willett, 1965 .

On the oscillatory behavior of the solutions of second order linear differential equations

D. Willett, D. Willett, 1969 .

On the discrete analogues of some generalizations of Gronwall's inequality

D. Willett, J. Wong, James S. W. Wong, 1965 .

Nonlinear vector integral equations as contraction mappings

D. Willett, 1964 .