Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
nam qua » nam quan, nam cua, nam mua
hieu ca » hieu cac, hieu cua, hieu va
cuu tre » cau tren, cau treo
ca nam » cua nam, cai nam, ha nam
qua va » quan va, qua van, vua va
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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 ky nang ((x hoi) OR (o hoi)). hieu ca nam qua va hanh tai ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (o hoi)). hieu ca nam qua va hanh tai ((cua tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) OR (o hoi)). hieu ca nam qua va hanh tai ((cua tre) or (cuu tre))*".