1. Grant, R. M. (1996). Toward a Knowledge-Based Theory of the Firm. Strategic Management Journal, 17(S2), 109–122. In the introduction (p. 110), Grant states, "If the resource-based approach is to offer a theory of the firm, we must be more precise as to what kinds of resources are important. The resources which are of overwhelming importance are those which are knowledge-based." DOI: https://doi.org/10.1002/smj.4250171110
2. Barney, J. (1991). Firm Resources and Sustained Competitive Advantage. Journal of Management, 17(1), 99-120. This seminal paper on the resource-based view (p. 101) defines firm resources to include "all assets, capabilities, organizational processes, firm attributes, information, knowledge, etc. controlled by a firm that enable the firm to conceive of and implement strategies that improve its efficiency and effectiveness." This explicitly includes knowledge as a key resource. DOI: https://doi.org/10.1177/014920639101700108
3. MIT Sloan School of Management. (2005). 15.390 New Enterprises, Lecture Notes, Session 3: Strategy. MIT OpenCourseWare. On page 10, under the "Resource-Based View of the Firm," the notes list "Know-how" and "Trade secrets" as examples of resources that can be a source of sustainable competitive advantage, reinforcing that knowledge is a strategic resource. Retrieved from https://ocw.mit.edu/courses/15-390-new-enterprises-spring-2005/resources/lecture3strate/