What 'sources' of knowledge do higher education students draw on, to prepare for exams? And has the pandemic made any difference? The study presented in this paper addresses these questions, in the belief that gaining awareness of the sources through which students learn is important for the instructional design of the courses and the evaluation methods as well. Framed within the 'Distributed Cognition' theory, the study is based on a questionnaire proposed in July 2021 (summer exam session) to all the students of two schools at Politecnico di Milano (the largest technical university in Italy); 5,369 students responded (16.5% of the total). The results show that students normally resort to a wide range of resources (lectures, lecturer's slides, group work with other students, notes taken by other students, etc.) and that, in the COVID-19 time, recorded lectures and 'exercises' (i.e. practical sessions with a teacher assistant) skyrocket in their perception of relevance, overcoming (almost all) other sources. Academies will need to face the challenge of students advocating for keeping this kind of support even after the COVID-19 era, which has the potential of revolutionising the way universities work, leading towards blended forms of education.