Shiva Purana
अष्टत्रिंशत्कलान्यासमेवं कृत्वा तु सर्वशः ॥ पश्चात्प्रणवविद्धीमान्प्रणवन्यासमाचरेत्॥ ७५ ॥
Thus making the Nyāsa of the thirty-eight Kalās the intelligent knower of Praṇava shall proceed with the Nyāsa of Praṇava.
english translation
aSTatriMzatkalAnyAsamevaM kRtvA tu sarvazaH ॥ pazcAtpraNavaviddhImAnpraNavanyAsamAcaret॥ 75 ॥
hk transliteration by Sanscript