Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cham duc » pham duc, cham soc, pham duy
thanh va » thanh van, hanh va, thanh ha
thanh vi » hanh vi, thanh ve, nhanh vi
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
cua tre » cua te, cuu tre, cua triet
tu sach » thu sach, su sach, te sach
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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 y nang o hoi. hieu ve cham duc va ((thanh vi) OR (thanh va)) ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang o hoi. hieu ve cham duc va ((thanh vi) OR (thanh va)) ((cua tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang o hoi. hieu ve cham duc va ((thanh vi) OR (thanh va)) ((cua tre) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang o hoi. hieu ve cham duc va ((thanh vi) OR (thanh va)) ((cua tre) or (cau tren))*.