Reference list order in a thesis Currently I am writing my master's graduate thesis. I am confused that which ordering style is more formal in a thesis reference list. For instance, consider the following three reference lists that I took as it is in order:


  [1] M. Fedrizzi, S. Giove Incomplete pairwise comparison and
  consistency optimization European Journal of Operational Research, 183
  (1) (2007), pp. 303–313
  
  [2] Z.S. Xu Goal programming models for obtaining the priority vector
  of incomplete fuzzy preference relation International Journal of
  Approximate Reasoning, 36 (3) (2004), pp. 261–270
  
  [3] P.T. Harker Alternative modes of questioning in the analytic
  hierarchy process Mathematical Modelling, 9 (3) (1987), pp. 353–360


Here the reference lists were not written in alphabetical order. Is there a general rule (convenience) for better formatting?
There are two systems: list the references in alphabetical order, or list the references in the order they are cited in the text. In my experience, which of these two systems is used depends on the academic field you're in. 

Before computers made searchable pdf files common, the first system was really useful when looking for a specific author or reference in the bibliography, and the second was really useful when looking for where a reference was cited in the text. 

With current technology, I don't think it really matters which system you use, although you should pick one and stick to it. My advice would be to check some other theses submitted to the same department to see how they did it.