Perhaps you should try some spelling variations:
thuat san » thuat toan, thuat song, thuat lanh
nang dai » nang dau, nang tai, nang cai
lang dai » lang hai, lang mai, lang chai
van hanh » van thanh, ban hanh, van ban
chat lo » chat co, chat bo, chat vo
tai cuu » tai cuc, tai buu, tai cua
van anh » van thanh, tuan anh, van minh
va chat » van chat, va phat, cao chat
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
san ky » sang ky, van ky, dan ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat san ky ((nang dai) or (lang dai)) hoi. hieu va chat lo ((van hanh) OR (van anh)) tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat san ky ((nang dai) OR (lang dai)) hoi. hieu va chat lo ((van hanh) OR (van anh)) tai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat san ky ((nang dai) or (lang dai)) hoi. hieu va chat lo ((van hanh) OR (van anh)) tai cuu tre*".