Citation Standards

Citations are part of the argument. They show where a claim can be checked, which convention a formula follows, and whether a statement is settled pedagogy, historical attribution, experimental evidence, or active research.

The default practice is to include a References section on mature pages. A compact formula card may cite fewer sources than a derivation page, but it should still point to authoritative references when the result is not purely definitional.

Source Hierarchy

Use sources according to the kind of claim:

• Textbooks and monographs for settled pedagogy, standard derivations, and notation.
• Original papers for discovery claims, priority claims, and historically specific statements.
• Review articles and lecture notes from recognized experts for active research areas.
• Experimental papers, collaboration papers, or data releases for experimental results.
• Official software documentation and peer-reviewed method papers for computational tooling.
• Standards bodies or primary constants references for units and constants.

Avoid using unsourced blog posts, anonymous notes, generated text, or informal summaries as the main authority for technical claims. They may be useful for orientation, but they should not carry the evidentiary weight of a mature page.

Where Citations Belong

Most pages should use a References section rather than dense footnotes. Inline attribution is appropriate when the historical or interpretive source matters, for example “Born’s 1926 scattering paper” or “von Neumann’s density-operator formulation.”

Use enough bibliographic detail that a reader can find the source:

• author names,
• title,
• edition when relevant,
• journal, volume, pages, and year for articles,
• publisher and year for books,
• arXiv identifier or DOI when helpful.

Minimum Expectations by Page Type

Concept pages should cite at least one standard textbook or monograph, and more when conventions or interpretations differ across references.

Derivation pages should cite a source for the result and any nontrivial method, especially when the derivation has common sign, normalization, or domain pitfalls.

Historical pages should cite original papers and a reliable secondary history source when possible.

Research-frontier pages should cite recent reviews or primary papers and must avoid presenting active claims as settled.

Software or numerical pages should cite both the relevant numerical method literature and the official documentation for tools or libraries when specific behavior matters.

Citation Hygiene

• Do not copy source prose.
• Do not cite a source that was not actually consulted.
• Do not use a citation to hide an unclear claim.
• Do not cite only the most famous source when a clearer or more precise source is needed.
• Check whether conventions in the cited source match the page convention.
• Prefer stable references over links that are likely to rot.

Common Mistakes

• Citing a textbook for a historical priority claim that should use the original paper.
• Citing an original paper for pedagogy when a modern source explains the assumptions better.
• Using a review article to imply consensus in an active research area.
• Leaving a formula card uncited because the formula is familiar.
• Treating a citation as proof that the page’s notation matches the source.

References

• Committee on Publication Ethics, Core Practices, for publication-integrity principles.
• M. Born, “Zur Quantenmechanik der Stoßvorgänge,” Zeitschrift für Physik 37, 863–867, 1926.
• J. von Neumann, Mathematical Foundations of Quantum Mechanics, Princeton University Press, 1955.
• J. J. Sakurai and J. Napolitano, Modern Quantum Mechanics, 3rd ed., Cambridge University Press, 2020.

Exercises

1. A page claims that the Born rule originated in scattering theory. What kind of citation should support that claim?

Solution

Use Born’s original 1926 paper for the historical claim, ideally alongside a reliable secondary source if the page discusses historical interpretation.

2. A page derives the harmonic-oscillator spectrum using ladder operators. Is one standard textbook citation enough?

Solution

Usually yes for a settled pedagogical derivation, provided the page’s conventions match the cited source. A second reference may be useful if the page compares normalization or phase conventions.