Looking at this question: Change of system of coordinates for the stress matrix
The comment by Samuel Weir (first one) links to a url that is is not displaying the equations (at least on all of my browsers). I found a link to the same basic page (written by the same author) that is displaying correctly on my computer.
Unfortunately I'm not high enough ranked to comment in the question to say "FYI, if this website isn't working for you, check out this one with the exact same information."
Any idea what I should/can do?