Can I use an unpublished but about to be published soon paper as a reference for a conference paper? Suggestions would be appreciated. Thank you!
The usual way of handling this situation is to use [in press] in the reference instead of the publication date to indicate that the publication is accepted but not yet available. Usually you should also provide soft copies of the to-be-published articles so that the reviewers can have access to them during the review process.
Note that some journals (there is no conference publishing in my field) will postpone the publication of your article until all in press articles are online/published to make sure the references don't need further editing and are correct and useful on the long haul.
Note: Do not use in press if you only speculate that the cited paper will be accepted, only after a firm notification of acceptance.