  A sizable rate of events, with several pairs of heavy-quarks produced
contemporarily by multiple parton interactions, may be expected at very high
energies as a consequence of the large parton luminosities. The production
rates are enhanced in hadron-nucleus reactions, which may represent a
convenient tool to study the phenomenon. We compare the different contributions
to ccbar bbar pairs production due to single and double parton scatterings, in
collisions of protons with nuclei at the CERN-LHC.
