*5.2. Limitations*

The results of this research should be considered in light of limitations. First of all, the data was collected using convenience samples. As a result, a certain level of caution may be required in generalizing the study results to a larger-scale population. Future studies may adopt a more systematic sampling approach in order to increase the validity of the scale. Second, this research includes marketing professionals working only in Lithuanian organizations. Future research may valuably validate the instrument among marketers working in other countries. Irrespective of the limitations mentioned above, we suppose that the GMaS is a valuable instrument that might be of good use to green marketing. This field demonstrates growing importance in the energy industry.

**Author Contributions:** Conceptualization, I.S. and N.V.-V.; methodology, I.S., G.D.-M. and N.V.-V.; software, G.D.-M. and N.V.-V.; validation, G.D.-M. and N.V.-V.; formal analysis, G.D.-M. and N.V.-V.; investigation, N.V.-V.; resources, N.V.-V.; data curation, N.V.-V.; writing—original draft preparation, N.V.-V.; writing—review and editing, I.S. and G.D.-M.; visualization, N.V.-V.; supervision, I.S. and G.D.-M.; project administration, I.S.; funding acquisition, I.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** This project has received funding from the European Social Fund (project No 09.3.3-LMT-K-712-02-0116) under a grant agreement with the Research Council of Lithuania (LMTLT).

**Data Availability Statement:** The data supporting results are securely kept in the PC of one of the researchers (N.V.-V.).

**Conflicts of Interest:** The authors declare no conflict of interest.
