Scientific research increasingly drives innovation and development of new technologies, and patent-to-paper citations can be used to trace this diffusion of knowledge and measure these science-to-technology spillover effects . However, the so-called “non-patent citations” in USPTO records do not contain authoritative identifiers, nor do they adhere to a standard format. They are strings written in free-form, often much too free, which makes it harder to systematically identify the articles or pieces of work cited. Here, we introduce Patci -- a tool that takes a citation string and probabilistically identifies matching records from a set of bibliographic databases. It currently permits matching to biomedical literature (21.5M PubMed records)...