Perhaps you should try some spelling variations:
sang dai » sang tai, lang dai, sang mai
hieu su » hieu sau, tieu su, hieu so
su phap » su pham, su phat, cu phap
va hanh » van hanh, va thanh, va danh
ky sang » ky nang, ky dang, ky tang
dai hoi » dai hoc, dai hai, dai moi
phap xu » phap tu, phap thu, phap ngu
di cua » dai cua, doi cua, de cua
vi cua » vai cua
tu sai » tu bai, tu cai, tu lai
tu san » thu san, tu ban, tu can
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 sai) or (tu san)) ky sang dai hoi. hieu su phap xu va hanh ((vi cua) OR (di cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sai) OR (tu san)) ky sang dai hoi. hieu su phap xu va hanh ((vi cua) OR (di cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sai) or (tu san)) ky sang dai hoi. hieu su phap xu va hanh ((vi cua) OR (di cua)) te".
• Adding a wildcard symbol may retrieve word variants: ((tu sai) or (tu san)) ky sang dai hoi. hieu su phap xu va hanh ((vi cua) OR (di cua)) te*.