Perhaps you should try some spelling variations:
dan khai » dang khai, van khai, dang khoi
khai dua » khi dua, khai quat, khai tuan
dua tren » dung tren
su sach » vu sach
so sach » so sanh, bo sach, co sach
cao hoi » cau hoi, cao hoc, tao hoi
cau tuc » cau truc, cau tu, cau luc
y nang » ky nang, ly nang, v nang
co hoi » co hoc, co loi
va cau » van cau, va cac, va dau
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau

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) or (so sach)) y nang ((cao hoi) OR (co hoi)). lieu va cau tuc va dan khai dua tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) y nang ((cao hoi) OR (co hoi)). lieu va cau tuc va dan khai dua tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) y nang ((cao hoi) OR (co hoi)). lieu va cau tuc va dan khai dua tren*".