Perhaps you should try some spelling variations:
thien van » thi van
hieu viec » nhieu viec, hieu ve, sieu viet
sach nuoc » sach duoc, cac nuoc, bach tuoc
doi cua » dai cua, hoi cua
doi cuu » doi cuoc
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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 ky nang ma hoi. ((hieu viec) or (thien van)) sach nuoc va van ((doi cuu) OR (doi cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. ((hieu viec) OR (thien van)) sach nuoc va van ((doi cuu) OR (doi cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ma hoi. ((hieu viec) or (thien van)) sach nuoc va van ((doi cuu) OR (doi cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. ((hieu viec) or (thien van)) sach nuoc va van ((doi cuu) OR (doi cua)) tre*.