ON PERIODS FOR STRING COMPACTIFICATIONS

Motivated by recent developments in the computation of periods for str ing compactifications with c = 9, we develop a complementary method wh ich also produces a convenient basis for related calculations. The mod els are realized as Calabi-Yau hypersurfaces in weighted projective sp aces of dimension four or as Landau-Ginzburg vacua. The calculation re produces known results and also allows a treatment of Landau-Ginzburg orbifolds with more than five fields.