Perhaps you should try some spelling variations:
doanh cao » doanh co, doanh bao, doanh cho
thi hang » thi hanh, thi nang, thi hong
tu sach » thu sach, su sach, te sach
cao cua » ca cua, co cua, cau cua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
ty nang » ky nang, ty xang, ty hang
ve cam » ve cham, ve cac, va cam
lo va » lo van, lao va, le va

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 ((ty nang) or (thi hang)) xa hoi. hieu ve cam ((lo va) or (ly va)) doanh cao cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (thi hang)) xa hoi. hieu ve cam ((lo va) OR (ly va)) doanh cao cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (thi hang)) xa hoi. hieu ve cam ((lo va) or (ly va)) doanh cao cua tre*.