In this paper, we are presenting an approach for the logical structure recognition of bibliographic references. The objective is to produce, for each reference (given in a display format, as postscript), structured data containing the hierarchy of fields recognized. As a result of variation among bibliographic references (in order and typographic format of fields, or writing style of the author, for example), we need a robust and tolerant system architecture. Thus, recognition is performed by a concept-oriented system that uses a model automatically built from a reference database. This model represents the reference fields and includes statistics on the occurrence of their terms. Recognition is achieved by a step-by-step activation of the more pertinent concepts. Each activated concept causes the execution of an appropriate searching agent. This architecture is robust and non-deterministic, allowing a solution even in difficult cases.