For an essay on how Oedipus Rex exemplifies or refutes Aristotle's definition of Tragic Hero, how can I find scholarly sources while on...

I take it you mean you are deployed on active service in
the military. What is the nature of the course you are taking? Is it an Internet
distance learning course? Or is it a military course offered through your branch of the
service?

If it is a long distance course, such courses
usually have academic research programs purchased that the student can access online.
There are several and each gives you access to a good number of online databases through
your course login. For example, you might login to the various databases with your
University student number and password. One example of such databases is JSTOR online
research database. I can't say with authority, but I would guess a military sponsored
educational program would have the same sort of thing. You would contact your course
representative for details.

In lieu of this option, an
alternative is to do a Google search--although Bing is often better for academic search
results--for the topic and/or authors' or critics' names you may have come across in
your readings. I've presonally found much good information on esoteric linguistic topics
in this fashion, so I would guess Oedipus Rex would also have much
information available. Google Scholar is devoted to scholarly sources, but the results
generally are to sources that require a course sponsored login as discussed
above.

Here are a few I found on Bing for you by using the
whole search term phrase Oedipus Rex Aristotle tragic hero+edu
(+edu filters for only academic
sources):
1.
Outline of Aristotle's Theory of Tragedy in the
POETICS
http://www2.cnr.edu/home/bmcmanus/poetics.html
2.
Oedipus
as the Ideal Tragic
Hero
http://www.classics.upenn.edu/myth/php/tragedy/index.php?page=oedhero
3.
Critics
names from a Wikipedia reference list
Bremer, J.M.; Dawe, R D.; Hyde, Isabel;
Moles, J. L.; Stinton, T. C. W.; Golden,
Leon,
http://en.wikipedia.org/wiki/Hamartia
4.
Aristotle
on Greek Tragedy; by Dr. Larry A. Brown, Professor of
Theater
http://larryavisbrown.homestead.com/Aristotle_Tragedy.html
5.
This
is a DOC: a Word Document:
On
Misunderstanding
www.nyu.edu/classes/reichert/cf/c1/Dodds_​Oedipus.txt.doc ·
Cached page · DOC file
6.
List of relevant ebooks and articles

http://lib.gccaz.edu/lmc/help/guides/litcriticism/OedipusRex.html
7.
Oedipus
the Cliché: Aristotle on Tragic Form and Content
Christopher S. Morrissey,
Department of Humanities, Simon Fraser
University
http://www.anthropoetics.ucla.edu/ap0901/oedipus.htm
8.
Oedipus:
The Definition of a Tragic Hero.
Krantz
http://faculty.weber.edu/dkrantz/en2500/Sample%20Essay%20Drama%202500.html
9.
Oedipus
the Wreck; Professor Eric Hibbison, J. Sargeant Reynolds Community
College
http://vccslitonline.vccs.edu/OedipustheWreck/research.htm