The second solution is then added in increments to the first solution while stirring to precipitate a mixture of {HEAD ~ oxygen containing compounds} of said first element, said second element, cerium, and {TAIL ~ terbium} 
of
The second solution is then added in increments to the first solution while stirring to precipitate a mixture of { HEAD ~ oxygen containing compounds } of said first element , said second element , cerium , and { TAIL ~ terbium }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL