Latex: Sorting and referencing using bibtex

Standard way of referencing in Latex is to put references number is square brackets, ,e.g., [3]. However, sometimes it is necessary to put references in superscript. To do this in TexShop it is enough to include package Natbib and use it like this:\usepackage[super,sort&compress,numbers]{natbib} This results in reference numbers as shown below
instead of standard way: