Vazquez-jauregui, E., Engelfried, J., Gülmez, E., et al., “First Observation of the Cabibbo-Suppressed Decays Xi(+)(c)->Sigma(+)pi(-)pi(+) and Xi(+)(c)->Sigma(-)pi(+)pi(+) and Measurement of Their Branching Ratios”, Physics Letters B, 666, 4, 299-304, 2008.