Sources published the same year by the same author are marked by “a”, “b” and “c” directly after the year to distinguish them from each other. The source you cite first in your text is given “a”, the following “b” and so on.
… (Alvesson 2010a:193) …
… (Alvesson 2010b:32) …
Alvesson, M. (2010a). Self-doubters, strugglers, storytellers, surfers and others: Images of self-identities in organization studies. Human Relations, 63(2), pp. 193-217. Available: SAGE Premier. Accessed: 17 June 2021.
Alvesson, M. (2010b). Interpreting interviews. London: Sage.