Books by Hiroyuki Yamauchi
Jissen Nihongo kyōiku sutandād
Jissen Nihongo kyōiku sutandādo
Purofishenshī kara mita Nihong
Purofishenshī kara mita Nihongo kyōiku bunpō
Purofishenshī to Nihongo kyōik
Purofishenshī to Nihongo kyōiku
Nihongo kyōiku sutandādo shian
Nihongo kyōiku sutandādo shian
OPI no kangaekata ni motozuita
OPI no kangaekata ni motozuita Nihongo kyōjuhō