Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
hanh ki » hanh vi, hanh ky, hanh kien
xuc van » duc van, luc van, vuc van
hieu va » lieu va, hieu qua
tu sach » thu sach, te sach, tu cach
nang ma » sang ma, nang cao, mang may
su sach » so sach, vu sach
tang ma » mang may, tang van
va cam » va cham, va cac, va cao
ki su » ky su

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (su sach)) vu ((nang ma) or (tang ma)) hoi. hieu va cam xuc van hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) vu ((nang ma) OR (tang ma)) hoi. hieu va cam xuc van hanh ki su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) vu ((nang ma) or (tang ma)) hoi. hieu va cam xuc van hanh ki su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) vu ((nang ma) or (tang ma)) hoi. hieu va cam xuc van hanh ki su triet*.