What is the correct usage of "the question of ..."?
I am currently writing my thesis, which addresses the question <em>of how to do X</em>. However, I am not sure whether the usage of <em>"the question of ..."</em> is correct. I found the following expressions while searching the web: 1. This thesis addresses the question of how to do X. 2. This thesis addresses the question how to do X. 3. This thesis addresses the question as to how to do X.Can someone tell which one is correct (and why)?I also sometimes use the expression <em>"the question of whether X is true"</em>. Do the same rules apply?Thank you,Dan