Perhaps you should try some spelling variations:
da phuong » dia phuong, dan phuong, day phuong
xa huong » xa phuong, va huong, xa muong
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
doi cua » dai cua, hoi cua
cham tu » pham tu, cam tu, chai tu
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va
cao hoc » co hoc, cho hoc, chat hoc
cua tre » cua te, cuu tre, cua triet

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 ky nang cao hoc. ((hieu ve) OR (hieu van)) cham tu ((xa huong) or (da phuong)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang cao hoc. ((hieu ve) OR (hieu van)) cham tu ((xa huong) OR (da phuong)) doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang cao hoc. ((hieu ve) OR (hieu van)) cham tu ((xa huong) or (da phuong)) doi cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang cao hoc. ((hieu ve) OR (hieu van)) cham tu ((xa huong) or (da phuong)) doi cua tre*.