Table 1.

Percentage of the articles reviewed from academic database.

S/N	Data base	URL	% of articles
1	Directory of Open Access Journals (DOAJ)	https://doaj.org/	4
2	Science Direct	http://www.sciencedirect.com/	20
3	Directory of Open Access Repository (OpenDOAR)	http://roar.eprints.org/7031/	4
4	Researchgate	https://www.researchgate.net/	8
5	IEEE Explore	http://www.ieeexplore.ieee.org/	4
6	ACM Digital library	http://dl.acm.org/	2
7	Google Scholar	https://scholar.google.com/	8
8	Springer	http://www.springer.com/	18
9	Wiley Online Library	http://onlinelibrary.wiley.com/	6
10	Taylor & Francis	http://taylorandfrancis.com/	8
11	EBSCOHOST	http://ebsco.com/	2
12	Web of Science	https://apps.webofknowledge.com/	4
13	Semantic Scholars	https://www.semanticscholar.org/	2
14	Scopus	https://www.scopus.com	10