Translation scholars have recently become interested in indirectness, a productive concept that stresses hidden dynamics in the process of translation, rendering visible the hierarchies between literatures and the complexities of literary translation. Since the publication of Toury’s seminal chapter in 1988, researchers working in various linguistic combinations and historical contexts have paid attention to indirect translation. However, there have been few attempts to reflect how it can be studied and documented. Based on both a review of previous research and the author’s study of twentieth-century Chinese literature translations in Spain, this article offers a systematic discussion of the different contributing sources (e.g. bibliographic databases and catalogues; paratexts; book reviews; sources about translators; and sources about contexts and translations) and methods (e.g. translation comparisons and interviews). The strengths and limitations of such sources and methods are assessed, with examples drawn from case studies to illustrate each category. This article also discusses methodological issues and offers valuable guidelines for research design.