# Help:Editing/House Style/Citations

## Citations

It is good to indicate where the information comes from. This is done in $\mathsf{Pr} \infty \mathsf{fWiki}$ in the last of the page in a section called Sources.

As stated on Help:Page Editing, the sources should be using a bulleted list, ordered by date of (first) publication, and after that alphabetically, sorted on the surname of the (first) author.

There are several templates which can be used:

### Hardcopy Sources

- Template:BookReference
- This is used to reference a specific book which will have been documented in the Books page. The idea of this is that if you have sourced the information for a page directly from a book, then it should be possible to provide the details of that book.

Example:

- 1969: C.R.J. Clapham:
*Introduction to Abstract Algebra*: $\S 4.17$: Theorem $28$

which can be found on the page Characteristic times Ring Element is Ring Zero.

- Template:Citation
- This is used to reference a specific article in a journal. This is still under development, as the individual Journal entries still need to be worked on.

Examples of their use can be found on various Mathematicians pages, for example:

- 1908:
*Mathematical Logic as Based on the Theory of Types*(*Amer. J. Math.***Vol. 30**: 222 – 262)

which appears on the page for Bertrand Russell.

The style of this is still evolving.

### Online Sources

There are templates for the following online sources. Each one has been crafted so as to produce a reference in the style requested by the online source in question.

- Template:MathWorld
- This provides a direct link to a page on the http://mathworld.wolfram.com/ website.

Example:

- Weisstein, Eric W. "Circular Sector." From
*MathWorld*--A Wolfram Web Resource. http://mathworld.wolfram.com/CircularSector.html

which can be found in the page Area of Sector.

- Template:Planetmath
- This provides a direct link to a page on the http://planetmath.org/ website.

Example:

*This article incorporates material from Urysohn's Lemma on PlanetMath, which is licensed under the Creative Commons Attribution/Share-Alike License.*

which can be found in the page Urysohn's Lemma.

An alternative format for the same link is:

*This article incorporates material from Urysohn's Lemma on PlanetMath, which is licensed under the Creative Commons Attribution/Share-Alike License.*

- Template:MacTutor Biography
- This provides a direct link to a page on the http://www-history.mcs.st-andrews.ac.uk/history/index.html website.

Example:

which can be found in the page for Hanna Neumann. Note that the link presentation is taken from the page the template is invoked from.

- Template:Khanacademy
- This provides a direct link to the Khan Academy.

Example:

- For a video presentation of the contents of this page, visit the Khan Academy.

which can be found in the page Limit of Sine of X over X/Geometric Proof.

- Template:Metamath
- This provides a direct link to Metamath.

Example:

which can be found in the page Principle of Transfinite Recursion.

- Template:Mizar
- This provides a direct link to Mizar.

Example:

- Mizar article TOPGEN_1:10

which can be found in the page Characterization of Boundary by Basis.

- Template:OEIS
- This provides a direct link to the On-Line Encyclopedia of Integer Sequences.

Example:

- This sequence is A002193 in the On-Line Encyclopedia of Integer Sequences (N. J. A. Sloane (Ed.), 2008).

which can be found in the page Square Root of 2 is Irrational.

- Template:TORI
- This provides a direct link to the TORI source site.

Example:

*This article incorporates material from Tetration on TORI, which is licensed under the Creative Commons Attribution/Non-Commercial/Share-Alike License.*

which can be found in the page Definition:Tetration.

- UPDATE: It is believed that this site may have closed down, as its links now 404.

- Template:SpringerOnline
- This provides a direct link to a page on the Springer Online Encyclopedia of Mathematics.

Example:

- Ring. O.A. Ivanova (originator),
*Encyclopedia of Mathematics*. URL: https://www.encyclopediaofmath.org/index.php/Ring

which can be found in the page Definition:Ring (Abstract Algebra).

### Acceptability of Online Sources

**NOTE: The above are currently the ONLY web resources which are to be used as general citation sources.** Others may be added to the above as and when they come to our attention as being particularly useful. So feel free to challenge this assertion if you find something which appears to be a particularly rich and productive resource.

Scholarly papers which are available online may usually also be cited.

What are *not* generally acceptable include:

- Lecture notes for university courses available online (because they do not stay online forever, and this causes dead links)
- Links to pages in homework help forums
- Discussion pages in
*any*web forum - Wikipedia -- not because we don't like them, but because as they are self-proclaimed tertiary source, there is no need to do so -- we would rather go to the actual source works. See also Wikipedia:Citing Wikipedia.