Perhaps you should try some spelling variations:
sang tao » hang tai
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
hieu va » lieu va, hieu qua
co sach » bo sach, cuon sach, hoc sach
nang ma » tang ma, sang ma, nang cao
luc va » duc va, tuc va, loc va
dai su » dai sua, dan su, lai su
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach y ((nang ma) or (sang tao)) hoi. hieu va cau luc va hanh ((dai su) OR (dai so)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach y ((nang ma) OR (sang tao)) hoi. hieu va cau luc va hanh ((dai su) OR (dai so)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach y ((nang ma) or (sang tao)) hoi. hieu va cau luc va hanh ((dai su) OR (dai so)) triet".
• Adding a wildcard symbol may retrieve word variants: co sach y ((nang ma) or (sang tao)) hoi. hieu va cau luc va hanh ((dai su) OR (dai so)) triet*.