Some open access journals (under the gold, and hybrid models) generate revenue by charging publication fees in order to make the work openly available at the time of publication.[73][24][25] The money might come from the author but more often comes from the author's research grant or employer.[74] While the payments are typically incurred per article published (e.g. BMC or PLOS journals), some journals apply them per manuscript submitted (e.g. Atmospheric Chemistry and Physics until recently) or per author (e.g. PeerJ).