Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
sach vu » sach va, sach tu, sach uu
hanh ki » hanh vi, hanh ky, hanh kien
vuc van » duc van, luc van, thuc van
xuc ban » duc ban, cuc ban, quoc ban
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
vu nang » vuc nang, va nang, vu dang
va cam » va cham, va cac, va cai
ma hoi » mai hoi, xa hoi, ma hoa
va cao » va cac, va co, va dao
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: su sach vu nang ma hoi. hieu ((va cam) or (va cao)) ((xuc ban) or (vuc van)) hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach vu nang ma hoi. hieu ((va cam) OR (va cao)) ((xuc ban) OR (vuc van)) hanh ki su triet.
• Adding a wildcard symbol may retrieve word variants: su sach vu nang ma hoi. hieu ((va cam) or (va cao)) ((xuc ban) or (vuc van)) hanh ki su triet*.