error check: don't allow entering an opinion if there already is an opinion with matching child no, author, and pubyr info (only works if both current and previously entered opinions are second-hand; Poling already had a check if they are both from the current ref)
error check: don't allow entering an opinion if there already is an opinion with matching child no, author, and pubyr info (only works if both current and previously entered opinions are second-hand; Poling already had a check if they are both from the current ref)


paleobiodb/pbdb-new,paleobiodb/pbdb-new,paleobiodb/pbdb-new,paleobiodb/pbdb-new,paleobiodb/pbdb-new