Hartland, P. C. (1950). Balance of interregional payments of New England. Brown University.
Chicago-viite (17. p.)Hartland, Penelope C. Balance of Interregional Payments of New England. Providence: Brown University, 1950.
MLA-viite (9. p.)Hartland, Penelope C. Balance of Interregional Payments of New England. Brown University, 1950.
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