Oliver C. Cox/world system theory

is there anyone who has written or seriously thought about Oliver Cox's
contribution to World-Systems Theory. in The Sociology of Oliver C. Cox,Jai
Press, there is an essay by Wallerstein on Cox's influence on him. however,
this essay is just a series of quotations by Cox with very little
discussion.

Cox's trilogy on the world system The Foundations of capitalism, Capitalism
and American Leadership and Capitalism as a System was published between
1959 and 1964. all of these volumes are long out of print. the Sociology of
Oliver C. Cox is edited by Herbert M. Hunter.