Perhaps you should try some spelling variations:
sach dao » lanh dao
hieu van » hieu va, thien van, lieu va
sang tao » hang tai
vu sach » vu bach, su sach, vu khach
van cam » van nam, van lam, van cau
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
dan vi » doan vi, don vi, dan va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach dao ((lang xa) or (sang tao)) hoi. hieu van cam ((luc va) OR (tuc va)) dan vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach dao ((lang xa) OR (sang tao)) hoi. hieu van cam ((luc va) OR (tuc va)) dan vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach dao ((lang xa) or (sang tao)) hoi. hieu van cam ((luc va) OR (tuc va)) dan vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach dao ((lang xa) or (sang tao)) hoi. hieu van cam ((luc va) OR (tuc va)) dan vi cua tre*.