We separate the steady-state distribution function f of energetic inner-zone protons into two parts: f = f1+f2, where (1) f1 is a solution of the homogeneous radial diffusion equation, associated with the external (diffusive) source, and (2) f2 is a solution of the inhomogeneous diffusion equation, related to the internal (Crand) source. By making special assumptions about the energy dependence of source and diffusion processes, we are able to evaluate analytically f as a function of energy E, pitch angle &agr;, and dipole shell parameter L. The analysis shows that the external source preferentially supplies protons of energies ≲30 MeV that mirror close to the equator, while the internal source is most important for protons having energies >50 MeV or pitch angles ≲50 ¿. Agreement between measured and computed energy spectra and pitch angle distributions for L values from L = 1.2 to L = 1.7 requires diffusion coefficients DLL(e)≈2¿10-11 L5 E-1 s-1 or DLL(m)≈3.75¿10-12 L9 E-1 sin2.7 &agr; s-1 (E in MeV), caused by electrostatic and magnetic fluctuations, respectively.