David Parnas, On the criteria to be used in systems into modules, Communications of the ACM 15, 12 (December 1972). This paper pointed out that the cost to modify a program is proportional to the size of the program, rather than the scope of the change, because the representation of objects appears in the syntax to access them.
Douglas T. Ross, Uniform Referents: An Essential Property for a Software Engineering Language, in J. T. Tou (Ed.), Software Engineering, Academic Press (1969).
Charles M. Geschke and James G. Mitchell, On the problem of uniform references to data structures, IEEE Transactions on Software Engineering TSE-1 (June 1975).