यदा यदा हि धर्मस्य (in Unicode)

yadā-yadā hi dharmasya

yadā yadā hi dharmasya

yadaa yadaa hi dhamasya

yada yada hi dharmasya

If you want to allow search using transliteration, there are a number of interesting algorithmic and non-algorithmic questions about the range of different transliteration mechanisms that people may use.

Also, for a reason that I don't quite understand, people transliterating Sanskrit can be very inconsistent about where they do and don't transcribe spaces. Are the spaces perhaps not present in the original? For example ग्लानिर्भवति might be transcribed as "glānir bhavati" or "glānirbhavati", which may also be treated differently for search purposes.

(I don't actually know any Sanskrit; I'm just interested in linguistics and writing systems.)