Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
qua tham » qua cham, qua than, qua thanh
tham duc » pham duc, tham du, than duc
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
ca tren » cau tren, cu tren, la tren
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) or (thuoc sach)) y nang o hoi. hieu qua tham duc va hanh vi ((cua tre) or (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) y nang o hoi. hieu qua tham duc va hanh vi ((cua tre) OR (ca tren)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) y nang o hoi. hieu qua tham duc va hanh vi ((cua tre) or (ca tren))*.