Arthashastra
पत्तयः पक्षयोर् अश्वाः पार्श्वयोः हस्तिनः पृष्ठतो रथाः पुरस्तात्, पर व्यूह वशेन वा विपर्यासः ॥
Infantrymen should be placed on the wings, horses on the flanks, elephants to the rear, and chariots in front, or the arrangement may be reversed depending on the specific battle formation.
english translation
pattayaH pakSayor azvAH pArzvayoH hastinaH pRSThato rathAH purastAt, para vyUha vazena vA viparyAsaH ॥
hk transliteration by Sanscript