Amongst others, it is mentioned in the Mafatih al-Ulum (Key of Sciences) of Khwarizmi and the Kitab al-Asrar (Book of Secrets) of Al-Razi.
Antara lain, disebutkan dalam Mafatih al-Ulum (Key of Sciences) darif Khwarizmi dan Kitab al-Asrar (Book of Secrets) dari Al-Razi.