Can I cite an unpublished Master Thesis? As title above.

This thesis is only available at the author's blog, though it is indeed a formal Master thesis. If I can cite it, how may I fill in all the blanks?

My concern is even if I cite it, the readers may be still unable to find it, if it is somewhat removed from his blog.
Just because it's not published doesn't preclude being able to cite it. You can't not cite the thesis if you're taking information from it!

The degree-granting institution should perpetually retain copies in its library, and most universities these days store PDF copies as well. A copy may be harder to track down, but a determined reader should have no enormous difficulty in getting a copy of the thesis.


  Example: 
  
  Smith B. (2013), General Relativity, MSc thesis, University of
  Cambridge, UK.