The Bardeen, Cooper and Schrieffer (BCS) approach is used to investigate the influence of anisotropy on the superconducting state in heavy fermionic systems or in the high-Tc oxide superconductors. We investigate the influence of anisotropy and nonlinearity on physical properties as the electron specific heat, the spin susceptibility, and Josephson tunelling. The moment approach has been used to calculate the single particle spectral functions for the tJ-model of a high-Tc superconductor. Within the framework of a mean field theory the energy gap is calculated together with spin-suseptibility and electron heat capacity. The results comply with cluster calculations.