• Directory of Open Access Journals (DOAJ) [2018] (https://doaj.org)
• Dimensions AI [2018] (https://app.dimensions.ai)
• CABI [2016] (http://www.cabi.org)
• Google Scholar [2014] (http://scholar.google.com)
• Google Scholar Matrics [2018] (https://scholar.google.co.id/)
• Garda Rujukan Digital (GARUDA) [2018] (http://garuda.kemdikbud.go.id)
• Science and Technology Index (SINTA) [2018] (https://sinta.kemdikbud.go.id)
• Indonesia One Search [2017] (http://onesearch.id)
• Bielefeld Academic Search Engine (BASE) [2016] (http://www.base-search.net)
• Crossref [2015] (http://www.crossref.org)
• Mendeley [2016] (http://www.mendeley.com)
• Indonesian Scientific Journal Database (ISJD) [2014] (http://isjd.pdii.lipi.go.id)
• Neliti [2016] (https://www.neliti.com)
• Scilit [2018] (https://www.scilit.net/journals/422602)
• PKP Index [2017] (http://index.pkp.sfu.ca)