Cite works and cross-reference

A scholarly text points in two directions: outwards, at the sources it relies on, and inwards, at its own theorems, figures and equations. This guide does both: a citation a reader can follow, the same source in the work's list of references, and links to parts of your own text and of other works.

Cite a source in a footnote

1. Directly after the claim that relies on the source, add a footnote marker with a label you will recognise, such as [^knuth1974].
2. Anywhere in the document, on a line of its own, write the footnote: the reference as you want it printed, with a DOI or an arXiv link when there is one.

The general case was analysed by Knuth.[^knuth1974]
 
[^knuth1974]: D. E. Knuth, "Structured programming with go to statements",
    *Computing Surveys* 6 (1974), 261–301. <https://doi.org/10.1145/356635.356640>

The page numbers footnotes 1, 2, 3 in the order they are first used, and collects them at the end of the work, each with a link back to where it was cited. The label is only for you: readers see the number. Citing the same source again reuses its footnote and its number. Notes that run over several lines are indented by four spaces after the first.

A DOI link takes the reader to the source in one click, and it keeps working when a publisher's site is reorganised, which is why it is worth looking up.

List the source in the work's references

A work also has a list of references, shown under its text, where a reader can open each one, copy it as BibTeX, RIS or CSL-JSON, or save it to their own citation library.

1. Close the editor and open the References tab of the work's form.
2. Choose Add Reference.
3. To reuse an entry from your citation library, search for it under From my library. To type a new one, choose Add new and fill in the type, title, authors, year, venue and DOI or URL. Tick Also add to my citation library to keep it for next time.
4. Choose Save.

The entry appears in the References tab, and on the published page under the text. Your citation library, where you can import BibTeX, RIS or Zotero exports in bulk, is at /library/citations on the site.

Why not [@key]

The bracket-and-at form, [@knuth1974] or [@knuth1974, p. 33], is the citation syntax pandoc reads, and LibreTimes reserves it for citations resolved against the references. That resolution is not built yet, so today the published page shows the text exactly as you typed it. Use footnotes until it is. What the syntax already does is keep a key intact: it is never turned into a link to a profile, although a key looks like a mention.

A LaTeX or Word file you import arrives already converted: its citations become numbered markers such as [1] in the text, and its bibliography becomes the references list.

Link to a part of your own text

Inside one document, a reference is an ordinary link to an anchor, a name you give the block.

1. Give the block an anchor:
   • a heading has one already, made from its text: ## Main result is #main-result;
   • a statement or a figure takes it on its fence: :::theorem[Lagrange]{#lagrange}, ::::figure{#fig-orbit};
   • any other block, such as a display formula or a table, takes it on an attribute line directly above it: {#eq-energy}.
2. Link to it with [link text](#name), writing the number in the link text yourself if the block has one.

:::theorem[Lagrange]{#lagrange number=2.2}
If $H$ is a subgroup of a finite group $G$, then $|H|$ divides $|G|$.
:::
 
{#eq-index}
$$
|G| = [G : H]\,|H| \tag{3}
$$
 
By [Theorem 2.2](#lagrange), or directly from [(3)](#eq-index), a group of
prime order has no proper non-trivial subgroups.

A click on either link scrolls to its target. The page does not fill in "Theorem 2.2" or "Figure 3" by itself yet, so the link text is yours: keep it in step with the numbers you give.

Choose names by what the block is, not where it is: #lagrange stays right when you add a theorem above it, #theorem-3 does not. A name starts with a letter, holds letters, digits, -, _, . and :, and is used once per document; one with a . or a : is written {id="eq:2.1"}.

Link to a part of another work

1. Open the other work and copy its address, which ends in /works/<id>.
2. Add the anchor after a #. A name its author chose gets user-content- in front of it, so {#lagrange} in that work is /works/<id>#user-content-lagrange. A heading's anchor, a printed page's #p412 and a problem's #p-412 are used as they are.
3. Link to the result: [Lagrange's theorem](https://libretimes.io/works/<id>#user-content-lagrange).

The prefix keeps an author's names from clashing with the page's own; links inside a document have it added for them, which is why only links from outside spell it out. The full table is in the reference.

The result

In the preview, each footnote marker is a small raised number linking to its note at the end, and each note links back. Each link to an anchor scrolls to its block. After you save, the work's References tab lists the sources you added, and its published page shows them under the text. A link whose target is missing goes nowhere, so after renaming an anchor, search the document for the old name.