How to embed citations into footnotes?

Question

How can I put a reference at the bottom of the page to something that I'm using? I need to do this the European way: so I want to place a small number at the end of the sentence that stands higher than the rest of the text. And at the bottom of the page, a horizontal line with the reference text/content.

So how can I do these two things?

• Tiny numbers at the end of a sentence;
• Reference at the bottom of the page with horizontal line on top.

Here's an example of what I mean.

Answer 1

Your question is actually about two things: How to produce a footnote, and how to embed a citation to a reference (here: an URL) into such a note.

Footnotes are produced with the standard LaTeX command \footnote{<Some text>}. LaTeX will add a superscript number at the position in the running text where you used \footnote, and will add the same number plus <Some text> at the bottom of the page. It will also add a rule to separate the actual notes from the running text.

To embed a citation into a footnote, you could simply write the appropriate text in the argument of \footnote. Another way that is suitable if you have a lot of references is to write them into a separate data file (in a special format called .bib) and to use specialized LaTeX packages (e.g., biblatex) to extract the data and integrate them into your main document -- e.g., in the form of footnotes.

In the following example, I'm using a data file called myreferences.bib that contains a data entry for the very question you asked -- the title, the year, and the URL. The entry is of the type @online and has the key foo12 (you could call it however you want). In your .tex file (and with the help of the biblatex package), I use the command \footcite{foo12} which will produce a footnote reference to your question. (Because I chose style=verbose, the full data will be printed; other styles would produce only an excerpt.) The \printbibliography command is used to produce the full data of all referenced entries at the end of the document.

EDIT: One more (still fairly basic) thing: The example must be compiled not only with (pdf)LaTeX, but with (pdf)LaTeX -- biber -- (pdf)LaTeX. Most editors suitable for LaTeX will offer automatic ways to do the necessary compilation steps.

\documentclass{article}

\usepackage[style=verbose]{biblatex}

\usepackage{filecontents}% to embed the file `myreferences.bib` in your `.tex` file

\begin{filecontents}{myreferences.bib}
@online{foo12,
  year = {2012},
  title = {footnote-reference-using-european-system},
  url = {http://tex.stackexchange.com/questions/69716/footnote-reference-using-european-system},
}
\end{filecontents}

% File is created and written to disk by the above package
\addbibresource{myreferences.bib}

\begin{document}

\null\vfill% to make the text height smaller for the example

\section{First section}

Some text.\footnote{Some text in a footnote.} Some more text.\footcite{foo12}

\printbibliography

\end{document}