Shiva Purana
पञ्चगव्याशनो मासम्मासञ्चान्द्रायणव्रती ॥ मासं कुशाग्रजलभुग्मासं श्वसनभक्षणः ॥ ३४ ॥
He ate five cows and observed a lunar fast for a month. For a month he ate water from the tip of a kusha grass and for a month he ate breath.
english translation
paJcagavyAzano mAsammAsaJcAndrAyaNavratI ॥ mAsaM kuzAgrajalabhugmAsaM zvasanabhakSaNaH ॥ 34 ॥
hk transliteration by Sanscript