{HEAD ~ The chosen model approach} contains {TAIL ~ modeling} of an external exhaust gas recycling system, variable inlet systems and systems with variable control valves 
contains
{ HEAD ~ The chosen model approach } contains { TAIL ~ modeling } of an external exhaust gas recycling system , variable inlet systems and systems with variable control valves
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH