Indexing star Google Scholar star World Cat star DRJI star ESJI star Index Copernicus star Scilit star EBSCO star Cosmos star Research Gate star DOAJ star ERIC star University of Washington ie star DUT findit star IJ Index Journal star J-Gate star Research Bib star Academic Keys star Sinta star CNKI Scholar star EDU index star OAJI.net star Academia.edu star Cite Seer star Citeulike star Science central.com star Harvard Library star Advanced Sciences Index