Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thanh ca » thanh cha, thanh cac, thanh ha
thanh co » thanh do, thanh ho, thanh vo
truc ban » thuc ban, truc dan, truc van
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu van
hieu va » lieu va, hieu qua
sach 2 » sach y
2 nang » v nang
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach 2 nang cao hoi. ((hieu ve) or (hieu va)) cau truc ban ((thanh co) OR (thanh ca)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach 2 nang cao hoi. ((hieu ve) OR (hieu va)) cau truc ban ((thanh co) OR (thanh ca)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach 2 nang cao hoi. ((hieu ve) or (hieu va)) cau truc ban ((thanh co) OR (thanh ca)) cua te".
• Adding a wildcard symbol may retrieve word variants: hoc sach 2 nang cao hoi. ((hieu ve) or (hieu va)) cau truc ban ((thanh co) OR (thanh ca)) cua te*.