The main reference to the CAPD library is the following article

T. Kapela, M. Mrozek, D. Wilczak, P. Zgliczynski,
CAPD::DynSys: a flexible C++ toolbox for rigorous numerical analysis of dynamical systems,
Communications in Nonlinear Science and Numerical Simulation, Volume 101, October 2021, 105578.

One may also consider to cite articles, where some of important algorithms implemented in the CAPD library have been developed.