Perhaps you should try some spelling variations:
thuat lanh » thuat lap, thuat san
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
hanh van » thanh van, khanh van, hanh va
van cac » van hac, van cau, van bac
cac duc » cac du, cao duc, cac dac
tu sach » thu sach, su sach, te sach
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thuat lanh)) ky sang ma hoi. hieu van cac duc va ((hanh van) or (hanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuat lanh)) ky sang ma hoi. hieu van cac duc va ((hanh van) OR (hanh tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuat lanh)) ky sang ma hoi. hieu van cac duc va ((hanh van) or (hanh tai)) cua tre*.