Perhaps you should try some spelling variations:
thai tuc » thai thuc, thai thuy, thai hoc
cau tren » cu tren, dau tren, ca tren
te sach » toc sach
sach ky » sac ky, sach y, sach ty
hieu va » hieu qua
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
nang o » nang co, nang ho, nang ro
tuc va » thuc va, truc va, tuc xa
vi cau » va cau, ve cau, di cau
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang o hoi. ((hieu va) or (lieu va)) thai tuc va danh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang o hoi. ((hieu va) OR (lieu va)) thai tuc va danh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: te sach ky nang o hoi. ((hieu va) or (lieu va)) thai tuc va danh vi cau tren*.