You can browse e-journals by subject in Oula-Finna, for example:
The SCImago Journal & Country Rank is a portal that lists journals by subject. Journal lists are developed from the information contained in the Scopus® database.
Journal Citation Reports (JCR) is a comprehensive and unique resource that allows the evaluation and comparison of journals using citation data drawn from over 10000 scholarly and technical journals included in the Web of Science -database. Journals are divided into over 200 categories by subject.
More full text databases in Oula-Finna
Useful tools for finding journals:
A scientific publication is openly accessible when both the scholarly community and the general public have free and unrestricted access to it on the Internet.
Guide to evaluation based on scientific publishing : Evaluating journals