{HEAD ~ Preferred compounds} include {TAIL ~ Bi oxide}, Co oxide, Cu oxide, Fe oxide, Mn oxide, and Pr oxide, and optionally Ag oxide 
{ HEAD ~ Preferred compounds } include { TAIL ~ Bi oxide } , Co oxide , Cu oxide , Fe oxide , Mn oxide , and Pr oxide , and optionally Ag oxide
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH