Figure 4.
The documents per sectors table has columns for sector and papers. The energy row lists Freedman and Stagliano, 2008, Dong and Burritt, 2010, Dragomir, 2012, Mosene et al., 2013, Bae, 2014, Frank et al., 2016, Miras-Rodriguez and Di Pietra, 2018, Argento et al., 2019, Traxler and Greiling, 2019, Tiron-Tudor et al., 2019, Beelitz et al., 2021, Eng and Fikru, 2022, Mamun, 2023, Vitolla et al., 2023, Slacik and Greiling, 2020 a, Slacik and Greiling, 2020 b, Ruggiero and Bachiller, 2023, Cormier and Gordon, 2001, Boiral, 2013, and Ates, 2023. The multi-line utilities row lists Mio, 2010, Chelli et al., 2019, and Paolone et al., 2020. The water utilities row lists Tregidga and Milne, 2006, Palme and Tillman, 2008, Vinnari and Laine, 2013, Bae, 2014, Tan and Egan, 2018, Passetti and Rinaldi, 2020, Ligorio et al., 2022, Venturelli et al., 2023, and Nicholas and Vedachalam, 2021. The multi-sector, also utilities row lists Gao et al., 2005, Gnana et al., 2013, Robertson and Samy, 2020, Soares et al., 2020, Ellimaki et al., 2021, Sepúlveda-Alzate et al., 2021, Alshiban and Al-Adeem, 2022, Imperiale et al., 2023, Radu and Dragomir, 2023, Manes-Rossi et al., 2020, Guthrie et al., 2017, and Nicolò et al., 2020. The utility in general row lists Bolívar, 2009, Shima and Fung, 2019, Pinheiro et al., 2021, Nicolò et al., 2023, and Greiling et al., 2014. The theories analysis table has Panel A, theories adopted, with columns for theories adopted, number of papers, and per cent. Single theories has 37 papers at 77 per cent, multiple theories has 11 papers at 30 per cent, and total has 48 papers at 100 per cent. Panel B, prospectives of theories adopted, has systems-oriented theories with 28 papers at 58.33 per cent, economic theories with 4 papers at 8.33 per cent, systems-oriented and economic with 4 papers at 8.33 per cent, other with 3 papers at 6.26 per cent, no theories with 9 papers at 18.75 per cent, and total with 48 papers at 100 per cent. The research method adopted table has columns for research method, number of papers, and per cent. Case study, single or multiple, interviews has 13 papers at 27 per cent, content analysis, historical analysis has 11 papers at 23 per cent, survey, questionnaire, other empirical has 16 papers at 33.33 per cent, commentary, normative, policy has 0 papers at 0 per cent, literature review has 0 papers at 0 per cent, mixed method has 8 papers at 16.67 per cent, and total has 48 papers at 100 per cent.Documents per sectors and theories and research methods adopted