Motivated by recent developments in the computation of periods for string
compactifications with c=9, we develop a complementary method which also
produces a convenient basis for related calculations. The models are realized
as Calabi--Yau hypersurfaces in weighted projective spaces of dimension four or
as Landau-Ginzburg vacua. The calculation reproduces known results and also
allows a treatment of Landau--Ginzburg orbifolds with more than five fields.Comment: HUPAPP-93/6, IASSNS-HEP-93/80, UTTG-27-93. 21 pages,harvma