Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
van tinh » van thinh, van minh, ban tinh
pham chu » pham chuc, pham thu, pham chi
hieu va » lieu va, hieu qua
tinh vi » trinh vi, tinh voi, tinh va
chu van » cuu van, chu han
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
te sach » toc sach
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: ((thuoc sach) or (te sach)) ky dang xa hoi. ((hieu ve) OR (hieu va)) pham chu van tinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (te sach)) ky dang xa hoi. ((hieu ve) OR (hieu va)) pham chu van tinh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (te sach)) ky dang xa hoi. ((hieu ve) OR (hieu va)) pham chu van tinh vi cua tre*".