References

RRÅ, R.kh., 8, 56.2
  saptāṃśena punardagdhaṃ dattvā drāvaiśca peṣayet //Context
RRÅ, V.kh., 13, 58.2
  ṭaṃkaṇaṃ śigrudhūmaṃ ca bhūnāgaṃ saptamaṃ bhavet //Context