How to cite a paper that looking for a journal for publication I am working on my second paper (as phd projects) which is an extension of my first paper. For my first paper, I will send it to a journal very soon. As I know acceptance of a paper by a journal is not an easy journey. Therefore, may I need to submit my paper for different journals (not at the same time) until it can find a place. My question is, how can I cite my first paper in my second one. I need to submit them at a very close time. For example, if I submit my first paper in this week (for example) then I may send the second one into two weeks (two weeks after the first one is submitted). 

Any help, please?
You can submit the first paper to a pre-print sever such as arxiv. Once, it appears in arxiv as a pre-print, you will get a citation information, which can then be used in the second paper.

I don't see any other way of doing it unless it appears somewhere as a pre-print or a published article.

Further, if you are citing a small portion (such as a method or a result) of first paper, you can replicate the same thing in the second paper with a note saying


  The initial approach of this method is to appear in the article entitled 'ABC Approach for ZYZ Analysis [draft]'.