* R: (:ja:理科年表): An (mostly) annual reference book published in Japan since 1925CE. Note that the actual published year is typically one year earlier than the nominal (book title) year.
</references>
* I: : Revised roughly by each decade. First edition 1935CE.
</references>
*D: Kyoritsu Great Dictionary of Chemistry
</references>
*X: Other usage examples
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