Abstract
This paper describes two models for semantic markup of bibliographic references, their advantages and disadvantages, and the challenges of automating a conversion from one format to the other. In one format a reference is captured as plain text. The semantic markup (author name, title, publication date, etc) is captured in attributes on the element containing the reference text. The other format is BITS, where each component of a reference is captured in its own element. The BITS model comes in two flavours, <element-citation> and <mixed-citation>, hence the extra half a model in the title. The conversion to BITS needs to support OpenURL linking and the Initiative for Open Citations (I4OC).