List works of the same author in order of date, as the two entries by Bowler above. The Word 6 sorting facility will do this automatically. But do not introduce an abbreviation unless you are going to use it frequently. A list of the abbreviations you have used, in alphabetical order as in the example below, should be given at the end of the dissertation, after the bibliography. However, common abbreviations such as i.e., etc., p. need not be listed.
Initials are the most usual form of abbreviation.
Initials standing for a periodical title, or for the name of an institution, may be written without full stops. If the full form is in italics, as in the case of a periodical title, the abbreviation should be in italics. You may find that you need to substantiate or explain a point, but do not want to interrupt your argument. You can do this by adding a footnote. Then type your footnote in the panel at the bottom.