Arthashastra
रथानां द्वौ त्रि भागाव् अङ्गेष्व् आवापयेत्, शेषम् उरस्यं स्थापयेत् ॥
Two-thirds of the chariots should be distributed to the flanks and wings, and the remainder stationed in the front.
english translation
rathAnAM dvau tri bhAgAv aGgeSv AvApayet, zeSam urasyaM sthApayet ॥
hk transliteration by Sanscript