Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
vien dai » hien dai
van hanh » van thanh, ban hanh, van anh
vien cac » vien da, gian cac, vien va
truc van » truc va, thuc van, truc ban
hanh di » hanh vi, hanh de, hang di
su sach » so sach, vu sach
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
x hoi » xa hoi, o hoi, x ho
di su » doi su, ki su, da 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 v nang x hoi. hieu ((((vien cac) OR (vien bach))) or (vien dai)) truc van hanh di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v nang x hoi. hieu ((((vien cac) OR (vien bach))) OR (vien dai)) truc van hanh di su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang x hoi. hieu ((((vien cac) OR (vien bach))) or (vien dai)) truc van hanh di su triet".
• Adding a wildcard symbol may retrieve word variants: su sach v nang x hoi. hieu ((((vien cac) OR (vien bach))) or (vien dai)) truc van hanh di su triet*.