Perhaps you should try some spelling variations:
nang lai » nang tai, mang lai, nang cai
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
vu nang » vuc nang, va nang, vu dang
lai roi » lai hoi, loi roi
duc van » duc va, duc tan, duc manh
hanh ki » hanh vi, hanh ky, hanh kien
va cam » va cham, va cao, va cai
ki su » ky su

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 vu nang lai roi. hieu ((va cam) or (va cac)) duc van hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu nang lai roi. hieu ((va cam) OR (va cac)) duc van hanh ki su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach vu nang lai roi. hieu ((va cam) or (va cac)) duc van hanh ki su triet*.