Perhaps you should try some spelling variations:
sang mai » sang tai, lang mai, hoang mai
hanh vai » hanh vi, hanh va, hanh tai
vai cuu » vai cua
va hanh » van hanh, va thanh, va danh
cao suc » cao su
cao duc » dao duc, giao duc, tao duoc
sang ma » tang ma, nang ma, sang tao
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky ((sang mai) or (sang ma)) hoi. hieu ve ((cao duc) OR (cao suc)) va hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky ((sang mai) OR (sang ma)) hoi. hieu ve ((cao duc) OR (cao suc)) va hanh vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky ((sang mai) or (sang ma)) hoi. hieu ve ((cao duc) OR (cao suc)) va hanh vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu cac ky ((sang mai) or (sang ma)) hoi. hieu ve ((cao duc) OR (cao suc)) va hanh vai cuu tre*.