## 3 Results
### Institutional Framework
#### 3.1.4 Approaches, Models, and/or Frameworks to Support Sustainability and SD  
Several papers assigned to the category \"institutional framework\" provided approaches, models, or frameworks that could be applied to support sustainability and SD in HEIs, as represented in Table 4. [PERSON] et al. [31], [PERSON] and [PERSON] [32], and [PERSON] and [PERSON] [33] addressed governance and leadership in the context of sustainability in HEIs. [PERSON] et al. [31] introduced the heuristic \"governance equalizer\" approach, adapting the approach from the existing governance literature to identify processes, instruments, and methods that promote the SD in HEIs (i.e., to analyze sustainability governance in HEIs). These authors suggested that conducting expert interviews could validate the \"governance equalizer,\" whereas further research on criteria development could reveal which equalizer dimensions are applied in the practice. In a case study, [PERSON] and [PERSON] [32] described how strategic leadership could support sustainability in an HEI and described a framework that could be used for strategic sustainable development (FSSD). The FSSD can be used as a tool to design effective approaches for sector-wide sustainability initiatives. [PERSON] and [PERSON] [33] outlined and applied an integrated approach, \"Higher Education Accelerating Development for Sustainability\" (HEADS), suggesting that it can be used to evaluate the higher education sector's role in facilitating national sustainability transitions towards a low-carbon society and, more specifically, their role in the solar photovoltaic (PV) niche development. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Article** & **Research Theme(s)** & **Research Method(s)** \\ \hline [PERSON] et al., 2018 [31] & Sustainability governance in HEIs & Survey \\ \hline \multirow{3}{*}{[PERSON] and Dyer 2017 [32]} & HEI strategic leadership for sustainability & \multirow{3}{*}{Case study} \\  & and the Framework for Strategic & \\  & Sustainable Development (FSSD) & \\ \hline [PERSON] and [PERSON] 2019 [33] & Leadership role of HEIs & Case study \\ \hline [PERSON] et al., 2017 [34] & Strategy towards sustainability & Literature review \\ \hline [PERSON] et al., 2015 [35] & Integrative approaches to SD at HEIs & Case studies \\ \hline \multirow{3}{*}{[PERSON] and [PERSON] 2018 [36]} & Strategic view of higher education social & \multirow{3}{*}{Literature review and framework} \\  & responsibilities & \\ \hline [PERSON]\(\tilde{\text{n}}\)[PERSON] et al., 2010 [37] & Sustainable behavior & Survey \\ \hline [PERSON] et al., 2018 [38] & Change management process and a & \\  & supporting toolset & Literature review and survey \\ \hline [PERSON] et al., 2019 [1] & Sustainability vision and sustainability & \multirow{3}{*}{Case study} \\  & strategy & \\ \hline [PERSON] et al., 2006 [39] & Managerial model for a sustainable HEI & Survey and literature review \\ \hline [PERSON] and [PERSON] 2015 [40] & SD integration process in an HEI & Case study \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Articles from the institutional framework category focusing on approaches, models, and/or frameworks to support sustainability and SD. In this literature review, we identified a publication by [PERSON] et al. [34] that proposed a conceptual framework for modeling HEI organizational environments to support sustainability. These authors reviewed international recommendations and initiatives for sustainability, frameworks, key topics fostering sustainability in HEI organizational environments, and a set of actions that support sustainability in these environments. They also presented a scheme to assess the degree of commitment, parity, difficulty, and institutional performance. Using two case studies, [PERSON] et al. [35] addressed the challenges and priorities associated with the use of the integrative approaches for SD implementation in HEIs.