Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
tai cua » thai cua, tai cuc, tri cua
kham ly » khao ly, khanh ly
vu kham » vu khanh
hieu vu » hieu va, hieu ve, hieu su
mai hoi » mai khoi, dai hoi, lai hoi
ty nang » ky nang, ty hang, ly nang
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi
ly van » le van, ly va, ly von

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ((ty nang) OR (ty xang)) ((ma hoi) OR (mai hoi)). hieu vu kham ly van hanh tai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ((ty nang) OR (ty xang)) ((ma hoi) or (mai hoi)). hieu vu kham ly van hanh tai cua tre~".
• Adding a wildcard symbol may retrieve word variants: thuat sach ((ty nang) OR (ty xang)) ((ma hoi) or (mai hoi)). hieu vu kham ly van hanh tai cua tre*.