Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hang hoi » hang hoa, hang hai, hang doi
luu hanh » huu han
hieu van » hieu va, thien van, lieu va
hoi cua » hoi chuc
luu van » cuu van, luan van
van cau » van dau, van hau, van chat
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
tu sach » su sach, te sach, tu cach
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: ((thu sach) or (tu sach)) ky dang xa hoi. hieu van cau ((luu van) or (luu hanh)) hang hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ky dang xa hoi. hieu van cau ((luu van) OR (luu hanh)) hang hoi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ky dang xa hoi. hieu van cau ((luu van) or (luu hanh)) hang hoi cua tre*.