P. Bueken, 3-DIMENSIONAL RIEMANNIAN-MANIFOLDS WITH CONSTANT PRINCIPAL RICCI CURVATURES RHO(1)=RHO(2)NOT-EQUAL-RHO(3), Journal of mathematical physics, 37(8), 1996, pp. 4062-4075
The main aim of this paper is the study of (nonhomogeneous) three-dime
nsional Riemannian manifolds with constant principal Ricci curvatures
rho(1)=rho(2) not equal rho(3). An error in a recent paper by McManus
is pointed out and corrected, and it is shown that the techniques intr
oduced by McManus provide a very simple method to obtain the complete
local classification of these manifolds, which was first given by Kowa
lski. (C) 1996 American Institute of Physics.