Shiva Purana
उद्गारे नाग आख्यातः कूर्म उन्मीलने स्थितः ॥ कृकलः क्षवथौ ज्ञेयो देवदत्तो विजृंभणे ॥ ३९ ॥
The vital air Nāga is for the activity of belching. Kūrma is for the activity of dosing the eyes; the vital air Kṛkara is the activity of sneezing and the vital air Devadatta is the activity of yawning.
english translation
udgAre nAga AkhyAtaH kUrma unmIlane sthitaH ॥ kRkalaH kSavathau jJeyo devadatto vijRMbhaNe ॥ 39 ॥
hk transliteration by Sanscript