Papers accepted, but not yet published, should be cited with the journal and the words "forthcoming" in the List of References, eg.
1. Von Breda, J. 2012. Hunger and poverty in South Africa. S Afr Med J, forthcoming.
Note: "Forthcoming" has replaced the term "in press" because changes in the publishing industry has rendered the previously used "in press" obsolete.
An ePub ahead of print is not the same as a forthcoming article. An ePub ahead of print signifies that the electronic version of an article has been published and the citation is included in PubMed, but that the print version of the article has not yet been published or indexed in full for PubMed. It is not necessary in your thesis, dissertation or research report to note that you have used the ePub ahead of print, provided that you cite the DOI.
It is not necessary to state "forthcoming" when citing a paper that has been accepted for publication, but which has not yet appeared, in the text of your research report, dissertation or thesis. The format follows that of a normal published citation, and is shown by the number of the reference in brackets or in superscript, eg.
Von Breda¹ encourages health care professionals to be especially aware of the burden of disease as a result of hunger and poverty in the South African context.
Health professionals are encouraged to be especially aware of the burden of disease as a result of hunger and poverty (1).