Arthashastra
एवं त्रि भाग ऊनो रथानाम् आवापः कार्यः ॥
Thus, the added surplus of chariots should be one-third less [than the number added to the flanks and the wings].
english translation
evaM tri bhAga Uno rathAnAm AvApaH kAryaH ॥
hk transliteration by Sanscript