Background: Technical communicators use special language information to describe technology products. Researching such information is part and parcel of their job and thus occupies a relevant share of their working time. Literature review: Numerous studies examine information needs and search techniques of various professionals, such as engineers or translators. However, very little is known about technical communicators' use of and requirements for information sources containing special language information. This article contributes to filling this research gap by discussing results of an empirical study. Research questions: 1. What types of nonhuman information sources do technical communicators use when researching special language information? 2. What properties do technical communicators expect from special language reference tools? Research methodology: We conducted a written online survey among technical communicators. In this article, we analyze and interpret survey data related to the two research questions. Results: Respondents use 14 major types of information sources for researching special language information. Half can be categorized as reference tools, while the other half are document-like. Respondents would like to have special language reference tools that are available electronically, can be adapted to their personal needs, and offer up-to-date information with good usability. Conclusions: Half of the information source types are document-like and can be used as text corpora. Thus, text corpus-management methods and tools should be promoted in technical communication practice and teaching. Technical communicators' requirements and wishes described in this article lay the groundwork for developing tailor-made special language reference tools.