Shiva Purana
धृतिमान्सुमहात्मा च तत्त्वदर्शीं निरुत्सुकः ॥ वेदाध्ययन सम्पन्नाश्चत्वारश्छिद्रदर्शिनः ॥ १६॥
The four sons of Chidradarśin were endowed with Vedic study. They were Dhṛtimat Sumahātman, Tattvadarśin and Nirutsuka.
english translation
dhRtimAnsumahAtmA ca tattvadarzIM nirutsukaH ॥ vedAdhyayana sampannAzcatvArazchidradarzinaH ॥ 16॥
hk transliteration by Sanscript