Once or twice I had encountered papers which used quite convenient citation styles, which combined numbered and parenthetical references. The list of references at the end of the paper is sorted alphabetically, as in Harvard referencing, but also all references are numbered, so it looks like this:
[1] AuthorA (2015) ...
[2] AuthorB (2000) ...
[3] AuthorC (2010) ...
In the text, one might use numbers to save space ("as shown in [2],..."), or parenthetical reference: "as shown by AuthorB (2000),...". And it's really convenient, since depending on the situation you might choose how to cite. I failed to find the name of such citation style - is it at all standardized, or is it just the invention of those papers that I had encountered (as far as I remember, they were preprints from arXiv)?