“…Although the database has some coverage issues (Fuentes Pujol et al, 2010) as well as data quality problems (Sánchez-Jiménez et al, 2017), it has been successfully used as an information source for meta-analysis and systematic reviews (Castellano et al, 2014;Catalá-López et al, 2012). It has also been abundantly used in the study of diverse fields through their dissertation literature, such as psychology (Musi-Lechuga et al, 2009), education (Curiel-Marín & Fernández-Cano, 2015, emergency medicine (Fernández-Guerrero, 2015), scientific medical information (Fernández-Guerrero et al, 2020) or sports science (Hernández-González et al, 2020). The scope of our research involves a very long period of time, from the late seventies to 2021, and a very wide range of scientific disciplines, that basically covers the whole spectrum of science.…”