  The spatial extents of particle emission source in high-energy collisions can
be measured using two-particle femtoscopic correlations. In collisions with
small multipli cities, such as proton-proton collisions, correlation functions
can be distorted by non-femtos copic effects, for example due to the
correlations that caused by energy-momentum conservatio n laws, jets and
mini-jets. To estimate these effects, a simulation of p+p collisions at
$\sqrt{s}$=200 and $\sqrt{s}$=510 GeV using PYTHIA 6.4.28 and HIJING 1.383, and
p+Au collisions at $\sqrt{s_{NN}}$=200 GeV using HIJING were performed. Charged
pion and kaon correlation functions obtained from the Monte Carlo generators
and their comparison to the experimental data are p resented.
