A-site-ordered perovskite oxides with formula AA'3B4O12 have a rich variety of physical and chemical properties. Most have Jahn-Teller active Cu2+ or Mn3+ at the square-planar A' site, but we have recently discovered that the A' site can also accommodate Mn2+ as in LaMn3V4O12. This undergoes an antiferromagnetic (AFM) transition to a 3-sublattice spin arrangement at TN = 44 K, where high spin Mn2+ with spin S = 5/2 orders with an angle of 120 degrees with respect to all four nearest neighboring Mn spins. This non-trivial magnetic structure may imply the existence of long-range magnetic interactions through the itinerant electron B-site V. To further study such perovskites, we have synthesized the new materials AMn3V4O12 (A = Ca, Na) and LaMn3(Ti3/4Sc1/4)4O12. GEM time is requested to study their cation order, and spin arrangements below low temperature spin ordering/freezing transitions.