Shiva Purana
प्राणानायम्य विधिवन्निर्विन्ध्यातटिनीतटे ॥ तपश्चचार सुमहदद्वन्द्वोऽब्दशतम्मुनिः ॥ ४ ॥
On the banks of the river Nirvindhyā, the sage who had controlled his breath and had freed himself from mutually clashing emotions performed a great penance for a hundred years.
english translation
prANAnAyamya vidhivannirvindhyAtaTinItaTe ॥ tapazcacAra sumahadadvandvo'bdazatammuniH ॥ 4 ॥
hk transliteration by Sanscript