One or more 510 fields should be added for items listed in the relevant standard or specialized bibliographies consulted by the cataloger, particularly "if these have been used to supply elements of the description" and also when "the cited source would serve to distinguish an edition (or variant) from similar editions (or variants), substantiate information provided by the cataloger, or provide a more detailed description of the publication being cataloged" (DCRM:B 7B14.2.). Use the form given in Standard Citation Forms for Rare Book Cataloging, or construct the form based on the guidelines given therein.
Houghton does not have a list of mandatory bibliographic resources which should always be cited in 510 fields. Instead, an annotated list of recommended references is maintained; this list is in a state of constant update and expansion.