  The method introduced in (Yehia H M 2006 J. Phys. A: Math. Gen. 39 5807-5824)
and (Yehia H M 2012 J. Phys. A: Math. Gen. 45 395209) is extended to construct
new families of several-parameter integrable systems, which admit a
complementary integral quartic in the velocities. A total of 12 new systems are
obtained, with a number of parameters ranging from 7 up to 16 parameters.
