Perhaps you should try some spelling variations:
dieu tra » dieu tri, kiem tra
mai hoi » mai khoi, dai hoi, lai hoi
sach ty » sach y, sach tu, sach thu
cau loc » hau loc, cau hoc, cau luc
va dang » van dang, va nang, va lang
ty nang » ky nang, ty xang, ty hang
vu sach » vu bach, su sach, vu khach
ma hoi » xa hoi, ma hoa, me hoi
va cau » van cau, va cac, va dau
loc va » hoc va, luc va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty nang ((ma hoi) OR (mai hoi)). lieu va cau loc va dang ((dieu cua) OR (dieu tra)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty nang ((ma hoi) or (mai hoi)). lieu va cau loc va dang ((dieu cua) OR (dieu tra)) triet~".
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang ((ma hoi) or (mai hoi)). lieu va cau loc va dang ((dieu cua) OR (dieu tra)) triet*.