Shiva Purana
यामेयामे यथा पूजा कार्या भक्तवरैर्हरे ॥ शिवरात्रौ विशेषेण तामहं कथयामि ते ॥ ४६॥
O Viṣṇu, I shall tell you how the worship is to be performed by the devotee, especially in every 3-hour period at the Śivarātri night.
english translation
yAmeyAme yathA pUjA kAryA bhaktavarairhare ॥ zivarAtrau vizeSeNa tAmahaM kathayAmi te ॥ 46॥
hk transliteration by Sanscript