On the convergence of Ces\`{a}ro means of negative order of double   trigonometric Fourier series of functions of bounded partial generalized   variation
  The convergence of Ces\`{a}ro means of negative order of double trigonometric Fourier series of functions of bounded partial $\Lambda$-variation is investigated. The sufficient and neccessary conditions on the sequence $\Lambda =\{\lambda_{n}\}$ are found for the convergence of Ces\`{a}ro means of Fourier series of functions of bounded partial $\Lambda$-variation. 
Ushangi Goginava and Artur Sahakian
math.AP