Shiva Purana
दैत्यदानवसंयोगाज्जातास्तीव्रपराक्रमाः ॥ सैंहिकेया इति ख्यातास्त्रयोदश महाबलाः ॥ ३४ ॥
Due to the intermixture of Daityas and Dānavas these sons became valorous and famous as Saiṃhikeyas. They are thirteen in number.
english translation
daityadAnavasaMyogAjjAtAstIvraparAkramAH ॥ saiMhikeyA iti khyAtAstrayodaza mahAbalAH ॥ 34 ॥
hk transliteration by Sanscript