Giambelli's formula may be derived as a consequence of Pieri's formula. The Porteous formula is a generalization to morphisms of vector bundles over a variety.
There is another Giambelli identity, expressing Schur functions as determinants of matrices whose entries are Schur functions corresponding to hook partitions contained within the same Young diagram. This too is valid for Schubert classes, as are all Schur function identities. For instance, hook partition Schur functions can be expressed bilinearly in terms of elementary and complete symmetric functions, and Schubert classes satisfy these same relations.