Perhaps you should try some spelling variations:
nang lai » nang tai, mang lai, nang cai
lai hoi » dai hoi, lai hoa, lai roi
hieu su » hieu sau, hieu so, hieu suat
tieu su » thieu so
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
vi cua » di cua
xu va » xu van, tu va, su 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 sac ky nang lai hoi. ((hieu su) or (tieu su)) chao xu va hanh ((vi cua) or (vai cua)) tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang lai hoi. ((hieu su) OR (tieu su)) chao xu va hanh ((vi cua) OR (vai cua)) tu.
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang lai hoi. ((hieu su) or (tieu su)) chao xu va hanh ((vi cua) or (vai cua)) tu*.