Brihat Parashara Hora Shastra
भर्दिकातो बुधो जातस्तथोल्कातः शनैश्चरः । सिद्धातो भार्गवि जातः संकटातस्तमोऽभवद् ॥ १९८॥
Budh, Śani, Śukr and Rahu are born from them.
english translation
bhardikAto budho jAtastatholkAtaH zanaizcaraH । siddhAto bhArgavi jAtaH saMkaTAtastamo'bhavad ॥ 198॥
hk transliteration by Sanscript