The Core Historical Literature Approach is based on the principle that effective preservation plans should focus on a specific discipline as a whole rather than on the holdings of an individual library and features the collection of extensive evaluative information from scholars. These users of the literature provide their expert opinions regarding historical publications' relative value and importance. This results in ranked bibliographic lists, addressing the fact that the quantity of materials in many subject areas that is at risk for deterioration is far greater than can be handled by available preservation resources. Mann Library has successfully applied this approach to its digitized collections of agricultural literature, the Core Historical Literature of Agriculture (CHLA) (http://chla.library.cornell.edu/), and home economics literature, the Home Economics Archive: Research, Tradition, and History (HEARTH) (http://hearth.library.cornell.edu/).