When the surnames are identical but the initials are different, include the initials of the authors in all in-text citations, regardless of the year of publication:
Dahl, R. (1983). The witches. Jonathan Cape.
Dahl, T. (1988). Working for love. Delacorte Press.
Parenthetical citations: (R. Dahl, 1983; T. Dahl, 1988)
Narrative citations: R. Dahl (1983) and T. Dahl (1988)
When the surnames and the initials are identical, the reference list should include their full first names [in square brackets] to indicate that they are not the same person. The first names are also included in the in-text citation, regardless of the year of publication:
Dahl, R. [Robert] A. (1982). Dilemmas of pluralist democracy: Autonomy vs. control. Yale University Press.
Dahl, R. [Roald]. (1983). The witches. Jonathan Cape.
Parenthetical citations: (Robert A. Dahl, 1982; Roald Dahl, 1983)
Narrative citations: Robert A. Dahl (1982) and Roald Dahl (1983)