Q: How much is citation one journal in another journal? How do I know this?
I am not sure I completely understand your question.
If you mean ‘how do you cite one journal (paper) in another journal,’ here are a couple of articles (based on the various style-guides) that you can refer to:
- APA Style cheat sheet: How to cite a journal article using APA Style
- How to cite an article: Quick tips on Vancouver and Harvard styles in citations