Yes you can but it is not preferable, let me say my opinion "I see this style is a bad one and sometimes frustrates me when I'm trying to read a non-open access paper how can I get the reference"
"This paper discusses the women entrepreneurship in terms of gender discrimination. Gender discrimination is prevailed dilemma of developing countries (Ashraf, 2015; Zeb, 2013; Sara, 2000)."........
I need such examples. If you have any example (published paper or abstract) so please attach with your answers.
For amateur writers especially in the case of postgraduate students, it is encouraged. However, it is not a practise among seasoned writers but no harm in citing in order to lend credit to our argument.
"It is not entirely unreasonable to include a citation in an abstract, if the reason you are citing it is because your paper is a major extension, rebuttal, or counterpoint to the cited article.
In that case, however, you do have the responsibility of providing the reference within the body of the abstract. For example,
"We extend upon the results of Smith [Journal of Very Important Results, 1, 374 (2012)] to include the effects of a doohickey at the end of the thingamajig."
In such a case, the abstract remains self-contained, with an important citation included. (This is especially essential if an author is well-known for multiple papers, in which case the reference can be used to distinguish the various works that could be intended.)
Large numbers of citations, however, should be avoided, as should "secondary" citations. Only the most critical literature for a paper should be cited, and that should normally be limited to one or two. Any more than that, and the abstract becomes hard to read."
If the author of the paper is proven a previous theory, then it should be referenced in the abstract. Also when the paper draws on a single previous work of some paradigmatic author, it should appeared in the abstract.