Where is Ma Cha Village?

I tried to find Ma Cha Village, which is supposedly along the road to Ta Phin village. But I unable to find it. It may seemed that what Let's Go Vietnam travel guide said is true, finding the way between the trailhead and Ma Cha village is difficult. To my surprise, I asked a few local people, and they seemed unsure of where is it too. It may be due to my wrong pronunciation anyway. So hiring a guide if you want to visit Ma Cha village is the better way. It's a small village housed mainly Hmong hill tribe.