Shiva Purana
सुनन्दो नन्दनश्चैव विश्वनन्दोपनन्दनौ ॥ शिष्यास्तस्य महात्मानो यैस्तद्ब्रह्म समावृतम्॥१०॥
They were Sunanda, Nandana, Viśvananda and Upanandana. They were the disciples of that noble soul. By them the Brahman was encircled.
english translation
sunando nandanazcaiva vizvanandopanandanau ॥ ziSyAstasya mahAtmAno yaistadbrahma samAvRtam॥10॥
hk transliteration by Sanscript