Numbering of alphabetically sorted bibliography

Currently, I am looking at the style for Journal of Exceptional People ( http://jep.upol.cz).It uses an interesting style in the articles.The bibliography is sorted alphabetically but it is also numbered.

[1] Adler ....
[2] Black ...

Is it possible coded this in the CSL?

I have to mention, that this is not necessary for the submission, due to instruction for authors describe the use of ISO 690 or APA style.And the second note: it seems like the bibliography is not edited in the editorial process, there is added the numbers only.Each article has a different structure of the bibliography in the issue (see http://jep.upol.cz/2017/Journal-of-Exceptional-People-Volume2-Number11.pdf).
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