common sources of ion of neodymium(III) cation vs iron(II) cation

neodymium(III) cation iron(II) cation | common sources of ion

neodymium(III) cation | neodymium(III) sulfate (2 eq) | neodymium(III) phosphate hydrate (1 eq) | neodymium(III) oxalate hydrate (2 eq) | neodymium(III) carbonate hydrate (2 eq) iron(II) cation | triirondodecacarbonyl (1 eq) | iron(II) sulfate hydrate (1 eq) | iron phthalocyanine (1 eq) | iron(II) molybdate (1 eq)