**3. Materials and Methods**

Having analyzed the conceptual approaches to seeking desirable customers' purchasing behavior with green marketing, we now focus on the articles in the field to examine the links between green marketing and customers' purchasing behavior. For this reason, we have chosen to conduct a systematic literature review in the paper at hand. A systematic literature review is a robust, rigorous, and transparent method that allows one to examine a corpus of scholarly literature and develop critical reflections, insights, future research questions, and paths [21].

The research aims to provide a comprehensive and systematic overview of green marketing and its impact on customers' purchasing behavior to develop an agenda that helps to identify promising areas for future research. This study includes existing papers that met the selection criteria defined in this paper without any limitations on the year of publication. The paper employs a conceptual framework that covers all the relevant stages of the literature-selection process (Figure 1). The research used the PRISMA approach which presents clear step-by-step instructions for a systematic way of reviewing literature.

Following the methodology of a systematic literature review described in Patticrew and Roberts [22], and applied, for example, by Kostagiolas and Katsani [23], Khan, and Qureshi [24], we systematically searched the literature to identify the articles that cover the problems of green marketing and its impact on customer purchasing behavior. Three databases, namely Scopus, Web of Science, and EBSCOhost, were searched using the following keywords: "green marketing", "customer behavior", "consumer behavior", "purchasing behavior", "purchasing intention", "consumption", "buying", "purchasing", "green purchase", and "green consumerism". The combination of three databases prevents possible shortcomings of one database. The search in the databases was addressed to papers containing at least one combination of "green marketing" and any other keyword from the list in their title, abstract, or keywords. Only papers in English that appeared in peer-reviewed academic journals were considered relevant. We refrained from analyzing other publication outlets such as monographs, books, book chapters, commentary essays, conference proceedings, and letters to the editor. Searches were performed on May 2022.

Papers with a different content focus (e.g., demarketing, conventional marketing) or works that did not present empirical evidence were excluded from the analysis. An initial search resulted in many papers not specifying the possible relationship between green marketing and customer purchasing behavior in the title, abstract, or keywords. We manually screened the titles, abstracts, and keywords to determine whether the identified papers addressed our research problem. In particular, we eliminated duplicate articles. We also have decided to exclude literature reviews from the analysis.

The first evaluation condensed the literature sample to 254 papers. After reading the contents, we reduced the working sample to 166 relevant research articles. We have created an Excel workbook for records of primary data of the 166 articles that formed the evidence base of the review.

**Figure 1.** Flowchart of the literature-selection process based on the PRISMA approach.
