Shiva Purana
मरुतो नाम ते देवा बभूवुस्तु महाबलाः॥ खगा एकोनपंचाशत्सहाया वज्रपाणिनः॥ १५॥
In the name of Maruts they became gods of great prowess. Thus traversing the sky the forty-nine Maruts became assistants of Indra.
english translation
maruto nAma te devA babhUvustu mahAbalAH॥ khagA ekonapaMcAzatsahAyA vajrapANinaH॥ 15॥
hk transliteration by Sanscript