Here is a link to an updated version: https://www.slideshare.net/khornberger/re-doing-a-paper-topic-and-selfcitation Shows why and how to cite your previous work using APA or MLA style.

1. Self-Citation (Citing your Previous Work) in MLA or
APA formats
Karen Hornberger
Library Media Specialist
Palisades High School

2. Sometimes writers need help determining what information to cite.
Rasmussen Library’s website clarifies this concern,“…the American Psychological
Association (APA) requires that all references "provide recoverable data" (APA, 2010, p.
180). Thus, things from your head, that you know because of expertise and experience
cannot be cited because your reader cannot "recover" or find them online or in a library;
thus you must find outside research to support your claims.”
This means that you must verify your knowledge from information published by an expert.
Rasmussen Library continues to state that there is “one exception: APA does allow for
self-citation if you are citing something you authored and published (for example a book
or an article). They do have cautions about this practice, however. For more information
see the Publication Manual's information on self-plagiarism (APA, 2010, p. 16).”
Source: http://rasmussen.libanswers.com/a.php?qid=258248

3. If you are more curious about citing common
knowledge, Princeton has an interesting article on
citing common knowledge.
Otherwise, you will want to know why and how to
self-cite work that you have previously written.

4. Why you might self-cite:
You may be writing a paper which relates to a topic that you have
already researched and written about.
It is natural that you may want to branch off of an earlier idea or deepen
that earlier idea.
To do so, you must identify the original work (paper). When it
originates from you, you will want to self-cite, so as not to self-
plagiarize.

5. Self-Plagiarism?
Walden University states on its website, “As strange as it may seem,
you are committing self-plagiarism if you reuse your work from previous
classes or degrees without appropriate citation.”
The key phrase here is, “without appropriate citation”
Source:http://writingcenter.waldenu.edu/656.htm#sthash.UoYYKb7B.dpuf

6. How to self-cite in APA format:
Again, from Walden University, we have a model. This models the citation in APA format:
“If you cite or quote your previous work, treat yourself as the author and your own previous course work as an
unpublished paper, as shown in the APA publication manual. For example, if Marie Briggs wanted to cite a paper she
wrote at Walden in 2012, her in-text citation might look like this:
Briggs (2012) asserted that previous literature on the psychology of tightrope walkers was faulty in that it
"presumed that risk-taking behaviors align neatly with certain personality traits or disorders" (p. 4).
And in the reference list:
Briggs, M. (2012). An analysis of personality theory. Unpublished manuscript, Walden University.
If your original work contained citations from other sources, you will need to include those same citations in the new
work as well, per APA. If Marie Briggs's earlier paper had cited Presley and Johnson, for example, it would look like
this:
According to Briggs (2012), recent psychologists such as "Presley and Johnson (2009) too quickly
attributed risk-taking to genetic factors, ignoring the social family issues that often influence the decision
to explore pursuits such as tightrope walking" (p. 5).”
Source: http://writingcenter.waldenu.edu/656.htm#sthash.UoYYKb7B.dpuf

7. Self-Citing in MLA format:
So, let’s use Marie Briggs as a model again. This time, we want to convert APA to MLA format.
Marie cites herself as the author and her in-text citation for her previous work would look like this in MLA:
Briggs asserted that previous literature on the psychology of tightrope walkers was faulty in that it "presumed that risk-taking
behaviors align neatly with certain personality traits or disorders" (4).
The sentence could also be written,
“Previous literature on the psychology of tightrope walkers was faulty in that it “presumed that risk-taking behaviors align neatly
with certain personality traits or disorders” (Briggs 4).
The citation within the Works Cited Page would look like this. Marie cites herself as the author following the format for
an unpublished paper. (this is assuming it is not published – if Marie actually published a paper or book she would cite
the published work with herself as author)
Briggs, Marie. "An Analysis of Personality Theory." 2012. TS.
To cite a source that Marie already cited in her work, Marie basically follows the rules for citing an indirect source.
Purdue OWL models how to cite an indirect source in MLA here.
According to Briggs, recent psychologists such as "Presley and Johnson too quickly attributed risk-taking to genetic factors,
ignoring the social family issues that often influence the decision to explore pursuits such as tightrope walking" (4).

8. Bottom Line:
When citing yourself, in whichever style you are utilizing, cite in-text
citations to identify yourself as the author.
On your Works Cited Page (MLA) or Reference List (APA), identify yourself
as the author using the format for an unpublished paper (or published, if you
have published it!)
Cite any indirect sources indicating yourself as the author.
Whether it is APA, MLA, Chicago/Turabian, etc. be sure to continue to follow
the format that you are expected to utilize.

9. For more on self-plagiarism:
From College and Research Libraries News
From Plagiarism Today
From iThenticate