Perhaps you should try some spelling variations:
viet sach » viet anh, dien sach, viet tech
kien sach » dien sach, vien bach, kien mac
diem cau » dieu can
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
vu sach » vu bach, su sach, vu khach
va anh » van anh, va hanh, va danh
di cau » da cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang xa hoi. lieu ((kien sach) or (viet sach)) nuoc va anh ((di cau) OR (diem cau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang xa hoi. lieu ((kien sach) OR (viet sach)) nuoc va anh ((di cau) OR (diem cau)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang xa hoi. lieu ((kien sach) or (viet sach)) nuoc va anh ((di cau) OR (diem cau)) tren".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang xa hoi. lieu ((kien sach) or (viet sach)) nuoc va anh ((di cau) OR (diem cau)) tren*.