1. A method for building a custom publication comprising: receiving a selection of units of content for inclusion in a custom publication, each unit of content selected from source publications; accessing a library of electronic source publications, the library having defined units of content within the same publications and storing source publication metadata for the defined units of content, wherein the custom publication includes references to defined units of content associated with the selected units of content; creating a set of custom publication units for an unpublished custom publication, wherein creating the set of custom publication units comprises copying the selected units of content and associating the copied, selected units of content with the unpublished custom publication; including additional content in at least one of the set of custom publication units of content; publishing the unpublished custom publication, wherein publishing the unpublished custom publication comprises: for common structural elements in the custom publication units, including the at least one custom publication unit including the additional content, determining corresponding structural element type, and applying consistent styling to each of the common structural elements in the set of custom publication units of content, including the at least one custom publication unit including the additional content, based upon the determined structural element type, to create a published custom publication with consistent styling; and providing the published custom publication in an electronic format.