title_body: References in e-books and printed books: Common style for both? If so, which one fits both media?
upvoted_answer: I don't think there is any reference style suitable for both print and ebook. Certainly footnotes look better in printed books, though I think EndNotes would be a better compromise solution for both medias. 
  
  One problem with ebooks is that the semantics can be different when you are trying to come up with something resembling footnotes. 
  
  In epub3 there is a solution called  which has been used by ibooks and kindle to present Notes popups. See my remarks on this question: How to handle footnotes when working with epub files  I don't know if book design software (like Indesign) can be configured to output these things as asides in epubs but footnotes in printed books. 
  
  I use a branch of XML (called Docbook XML) which allows for (printed) footnotes and (HTML) endnotes to be output from the same source. See http://www.sagehill.net/docbookxsl/Footnotes.html Configuring this solution is not easy although I have done it..... To my knowledge Docbook xsl does not output footnotes into asides, although I will check on that. 
  
  As for styling, obviously you can do it easily in HTML/epub, while in software for printing book design you may have to apply the style manually. 
  
  The key problem is that print solution can't implement a footnote easily and cross platform. In the answer I gave before (see above URL) I recommended waiting until ASIDES were formally supported in KF8 before I start doing them. (although a popup note certainly sounds good in theory).