Justin Blake,1960.Jacob Morris on Unproductive Employment:A
Criticism. Science and Society: 24,pp.171,173.

Jacob Morris,1958. Unemployment and Unproductive Employment,
Science and Society,22,pp.195.

Joseph Gillman,1965. Prosperity in Crisis,New York,pp.23;Jacob
Morris,1958.Unemployment andUnproductive Employment,Science and Soci-
ety,22,pp.194.
万分感谢！