Brihat Samhita
असिमुशलं सप्तदशादष्टादशतो अपि वा तदनुवक्रे । दस्युगणेभ्यः पीदां करोत्यवृष्टिं सशस्त्रभयाम् ॥ ६-०५ ॥
If he should begin to retrograde from the 17th or the 18th constellation from that of his reappearance such retrograde motion is known as Asimusala; when Mars is in his reretrograde motion, bands of robbers will be afflicted with distress and there will be drought and wars in the land.
english translation
asimuzalaM saptadazAdaSTAdazato api vA tadanuvakre । dasyugaNebhyaH pIdAM karotyavRSTiM sazastrabhayAm ॥ 6-05 ॥
hk transliteration by Sanscript