How to Cite an Unpublished Manuscript in APA?

Can you please tell me if there is any specific APA format for referencing unpublished manuscript? I want to cite a research paper of my senior which is not formally published in any journal till now. He has submitted it in ELK Asia Pacific Journal for a month now but the publication is still under process. So, is there any way by which I can cite it? Because it is unpublished, what would I fill out in the Year section?