Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu ve » hieu va, hieu van
tu sach » thu sach, su sach, tu cach
te sach » toc sach
hoc hoi » hoc khoi, hoc hoa, hoc noi
v nang » va nang, vu nang, van nang
y nang » ky nang, ly nang, may nang
ve cac » va cac, vien cac
cac su » cach su, cac sau, cac du
va dao » ca dao
dao di » dao do, dao du, dao li
di cau » da cau, diem cau
su va » su van, tu va

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

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