1. Pressman, R. S., & Maxim, B. R. (2020). Software Engineering: A Practitioner's Approach (9th ed.). McGraw-Hill. In Chapter 21, "Software Testing Strategies," Section 21.3.2, "Integration Testing Strategies," it is explicitly stated: "Top-down integration testing is an incremental approach... The processing of lower-level modules is simulated by a stub... A stub is a 'dummy subprogram' that uses the subordinate module’s interface." This contrasts with Bottom-up testing, which "requires driver modules to be built."
2. Sommerville, I. (2016). Software Engineering (10th ed.). Pearson. In Chapter 8, "Software Testing," Section 8.3.2, "Integration testing," the text clarifies: "In top-down testing, you start with the high-level components... you replace the lower-level components with stubs... In bottom-up testing, you start with the most fundamental components... To test these components, you need to write drivers." (p. 243).
3. Koomen, T., & van der Aalst, L. (1999). Test Process Improvement: A practical step-by-step guide to structured testing. Addison-Wesley. Chapter 5 discusses test design techniques, where the roles of stubs and drivers in top-down and bottom-up integration, respectively, are defined as a foundational concept in structured testing.