Generalized holomorphic functions and Clifford analysis. Obolashvili, E. (1997) Memoirs on Differential Equations and Mathematical Physics
Generic simplicity of eigenvalues for a Dirichlet problem of the bilaplacian operator. Pereira, Marcone C. (2004) Electronic Journal of Differential Equations (EJDE) [electronic only]
Green's function and convergence of Fourier series for elliptic differential operators with potential from Kato space. Serov, Valery (2010) Abstract and Applied Analysis