Referenced Publication Year Spectroscopy (RPYS) was recently introduced as a method to analyze the historical roots of research fields and groups or institutions. RPYS maps the distribution of the publication years of the cited references in a document set. In this study, we apply this methodology to the oeuvre of an individual researcher on the occasion of a Festschrift for Andras Schubert's 70th birthday. We discuss the different options of RPYS in relation to one another (e.g. Multi-RPYS), and in relation to the longer-term research program of algorithmic historiography (e.g., HistCite) based on Schubert's publications (n=172) and cited references therein as a bibliographic domain in scientometrics. Main path analysis and Multi-RPYS of the citation network are used to show the changes and continuities in Schubert's intellectual career. Diachronic and static decomposition of a document set can lead to different results, while the analytically distinguishable lines of research may overlap and interact over time, and intermittent.