Perhaps you should try some spelling variations:
truong doi » truong dai, trong doi, truong hoi
so sach » so sanh, bo sach, co sach
doi cua » dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
ty nang » ty xang, ty hang, ly nang
hieu va » lieu va, hieu qua
o hoi » co hoi, o hoc, o hai
tu xa » tu xay, tu va, tu ma
te xa » te va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((ty nang) OR (ky nang)) o hoi. hieu va cac ((tu xa) or (te xa)) truong doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ty nang) OR (ky nang)) o hoi. hieu va cac ((tu xa) OR (te xa)) truong doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ty nang) OR (ky nang)) o hoi. hieu va cac ((tu xa) or (te xa)) truong doi cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ((ty nang) OR (ky nang)) o hoi. hieu va cac ((tu xa) or (te xa)) truong doi cua tre*.