What if I can't find a DOI?

Related questions

1. How do I know if my article has been cited?
2. How do I register with Google Scholar?
3. What's the difference between journal and article?
4. How do you check how many times an article has been cited?
5. How do I find an ISI Journal?
6. What is ISI Scopus?
7. How do you get references when you have none?
8. What is a DOI number in a journal article?
9. What is the difference between newspaper and journal?
10. What's the difference between an article and a website?

Tags

1. #journal
2. #entry
3. #means
4. #direct
5. #uncertain
6. #there
7. #given
8. #assigned
9. #whether
10. #often
11. #homepage
12. #document
13. #article
14. #number
15. #electronic
16. #reference
17. #searching
18. #online