Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
cau tren » cu tren, ca tren, cau treo
dau tren » dau tien, dat tren, dau tieng
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
ve cac » va cac, vien cac
va dan » ca dan, va dao, va dau

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang cao hoi. hieu ve cac thuc va dan ca ((cau tren) OR (dau tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang cao hoi. hieu ve cac thuc va dan ca ((cau tren) OR (dau tren))~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang cao hoi. hieu ve cac thuc va dan ca ((cau tren) OR (dau tren))*.