{{Cite book| publisher = SAGE Publications Ltd| doi = 10.4135/9781529732306| isbn = 978-1-5297-3230-6| last1 = Robert| first1 = Emilie| last2 = Ridde| first2 = Valéry| title = Dealing With Complexity and Heterogeneity in a Collaborative Realist Multiple Case Study in Low- and Middle-Income Countries| location = 1 Oliver's Yard, 55 City Road, London EC1Y 1SP United Kingdom| access-date = 2020-03-28| date = 2020-03-24| url = https://methods.sagepub.com/case/complexity-heterogeneity-collaborative-realist-low-middle-income-countries}}