Shiva Purana
एकरुद्रं च तच्छक्तिं पश्चादीशदले ऽर्चयेत् ॥ त्रिमूर्तिं तस्य शक्तिं च पूजयेदग्निदिग्दले ॥ ८ ॥
Afterwards he shall worship Ekarudra and his Śakti in the north-eastern petal. He shall worship Trimūrti and his Śakti in the South-eastern petal.
english translation
ekarudraM ca tacchaktiM pazcAdIzadale 'rcayet ॥ trimUrtiM tasya zaktiM ca pUjayedagnidigdale ॥ 8 ॥
hk transliteration by Sanscript