2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/202812Motivated 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.HUPAPP-93/6, IASSNS-HEP-93/80, UTTG-27-93. 21 pages,harvmacHigh Energy Physics - Theorytext