Brihat Parashara Hora Shastra
मण्डूकापरपर्याया त्रिकूटाख्यदशा द्विज । लग्नसप्तमयोर्मध्ये यो राशिर्बलवान् भवेत् ॥ १७९॥
Under the Manduk Dasha system the Dasha commences from Lagn, or Yuvati Bhava, whichever is stronger.
english translation
maNDUkAparaparyAyA trikUTAkhyadazA dvija । lagnasaptamayormadhye yo rAzirbalavAn bhavet ॥ 179॥
hk transliteration by Sanscript