Shiva Purana
तत्रोक्तः परमो धर्मश्चर्याद्यात्मा चतुर्विधः ॥ तेषु पाशुपतो योगः शिवं प्रत्यक्षयेद्दृढम् ॥ १७ ॥
The great virtue of Śiva mentioned before is four-fold with regular performance and observance as the basic Atman for them. Among them the Pāśupata yoga facilitates the direct perception of Siva.
english translation
tatroktaH paramo dharmazcaryAdyAtmA caturvidhaH ॥ teSu pAzupato yogaH zivaM pratyakSayeddRDham ॥ 17 ॥
hk transliteration by Sanscript