  The Large Hadron Collider has provided large amounts of data on collisions of
small systems, such as proton-proton and proton-lead at unprecedented collision
energies. Their space-time size and structure can be inferred from the
measurement of the femtoscopic correlations for pairs of identical particles.
The analysis is complicated by the presence of significant additional sources
of two-particle correlations, which influence the correlation function in the
region of the femtoscopic effect. In this work we use p-Pb events generated in
a model that includes such additional correlation sources to characterize them
and propose a robust method of taking them into account in the extraction of
the femtoscopic information.
