Cochrane overviews of reviews	Pollock M, Fernandes RM, Becker LA, et al. Chapter V: Overviews of Reviews. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.3 (updated February 2022). Cochrane, 2022. Available from: www.training.cochrane.org/handbook.
Grounded formal theory *Primary grounded theory studies	Strauss AL, Corbin J. Basics of qualitative research: techniques and procedures for developing Grounded Theory. Thousand Oaks: Sage; 1998. Eaves YD. A synthesis technique for grounded theory data analysis. J Adv Nurs. 2001;35:654-663
Mega-aggregation framework Synthesis	Hendricks L, Eshun-Wilson I, Rohwer, A. A mega-aggregation framework synthesis of the barriers and facilitators to linkage, adherence to ART and retention in care among people living with HIV. Syst Rev. 2021:10, 54.
Mega-ethnography	Toye F, Seers K, Hannink E, et al. A mega-ethnography of eleven qualitative evidence syntheses exploring the experience of living with chronic non-malignant pain. BMC Med Res Methodol. 2017;17:116.
Umbrella review approach *Systematic review of QES	Aromataris E, Fernandez R, Godfrey CM, et al. Summarising systematic reviews: methodological development, conduct and reporting of an umbrella review approach. Int J Evid Based Healthc. 2015;13:132-140.