Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
thanh de » hanh de, thanh ve, thanh do
cau theo » cau thi, cau tao
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
ve cac » va cac, vien cac
de cau » ke cau, le cau, ve cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((y nang) or (v nang)) cau hoi. hieu ve cac duc va thanh de cau theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (v nang)) cau hoi. hieu ve cac duc va thanh de cau theo.
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) or (v nang)) cau hoi. hieu ve cac duc va thanh de cau theo*.