Perhaps you should try some spelling variations:
dat ngoc » dat nuoc, dau ngoc, dang ngoc
lang van » dang van, tang van, hoang van
va thanh » gia thanh, ban thanh, le thanh
vu sach » vu bach, su sach, vu khach
via cua » gia cua, gian cua, giau cua
va tinh » may tinh
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
hieu ve » hieu van
van hoi » van hoa, van hoc, van hoe
ky lang » ky nang, ky dang, ky tang

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 ky lang van hoi. ((hieu ve) OR (hieu va)) dat ngoc ((va thanh) or (va tinh)) via cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky lang van hoi. ((hieu ve) OR (hieu va)) dat ngoc ((va thanh) OR (va tinh)) via cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky lang van hoi. ((hieu ve) OR (hieu va)) dat ngoc ((va thanh) or (va tinh)) via cua tre*".