Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
vu nang » vuc nang, va nang, vu dang
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
hanh ki » hanh vi, hanh ky, hanh kien
tu sach » thu sach, te sach, tu cach
ma hoi » mai hoi, xa hoi, ma hoa
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 hoi. hieu va cam ((xuc van) or (duc 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 hoi. hieu va cam ((xuc van) OR (duc 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 hoi. hieu va cam ((xuc van) or (duc van)) hanh ki su triet*".