Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
nang tai » tang tai, sang tai, nang cao
van hanh » van thanh, ban hanh, van anh
hang tai » hang va, dung tai
nang mai » nang ma, lang mai, nang cai
sach vu » sach va, sach tu, sach uu
hieu va » lieu va, hieu qua
xuc van » duc van, luc van, vuc van
hanh ki » hanh vi, hanh ky, hanh kien
tu sach » thu sach, su sach, te sach
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 vu ((nang mai) or (((nang tai) OR (hang tai)))) 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 vu ((nang mai) OR (((nang tai) OR (hang tai)))) 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 vu ((nang mai) or (((nang tai) OR (hang tai)))) hoi. hieu va cam xuc van hanh ki su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach vu ((nang mai) or (((nang tai) OR (hang tai)))) hoi. hieu va cam xuc van hanh ki su triet*.