Yes you will find some older books with the use of jitsu or even the awful jiu-jitsu spellings. Honestly there was no standardization of romanization. "The lack of solidarity in romanisation of Japanese (both by Japanese nationals and others) when these words were first borrowed brought all of this on - and it stuck. At least nowadays the Japanese Language Council has prescribed one system of romanization." - Daniel Lee on E-budo
Honestly this is a lost battle. No matter how many times I correct the internet - people keep writing 'jitsu' Cool. I lose. But if you want to have a little more correctness in your use of the Japanese language for your writings, I do suggest the utsu spelling.
Long had I believed both writings were OK. Long have I sworn my teacher in Japan said 'jitsu'. And even my business card says 'jitsu'. The window at my dojo says 'jitsu'. I was wrong.
from Jisho
術
art; means; technique - the kana for it's pronounciation is quite clear じゅつ = jutsu.
from romanjidesu
術
art; technique; skill; means; trick; resources; magic again in katakana - ジュツ = jutsu
again - ジュツ = jutsu
Jutsu - Wikipedia
Last Chrismas I had the pleasure of sitting down with 20 Japanese teachers studying English at my wife's school. I asked them the jitsu versus jutsu question. They ALL told me it was jutsu. Still I refused to believe and pressed them further. They speculated that English speakers simply cannot easily pronounce jutsu so there was some pronounciation drift. Simply we like saying jitsu, just like Japanese people say 'wapuro' instead of word processor.
