Shiva Purana
द्वारपालान्समभ्यर्च्य भद्रादींश्चतुरःक्रमात् ॥ समुद्रश्च विभद्रश्च सुनंदश्च विनंदकः ॥ ११ ॥
One should worship the doorkeepers, headed by Bhadra, in four orders. Samudra Vibhadra Sunanda and Vinanda.
english translation
dvArapAlAnsamabhyarcya bhadrAdIMzcaturaHkramAt ॥ samudrazca vibhadrazca sunaMdazca vinaMdakaH ॥ 11 ॥
hk transliteration by Sanscript