Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
cau treo » cau tren, cau triet, cau trieu
hieu van » hieu va, thien van, lieu va
hanh hai » thanh hai, nhanh hai, hang hai
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
van cac » van hac, van cau, van bac
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc va
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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 o hoi. hieu van cac ((xuc va) or (luc va)) hanh hai ((cau treo) OR (cau theo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang o hoi. hieu van cac ((xuc va) OR (luc va)) hanh hai ((cau treo) OR (cau theo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang o hoi. hieu van cac ((xuc va) or (luc va)) hanh hai ((cau treo) OR (cau theo))".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang o hoi. hieu van cac ((xuc va) or (luc va)) hanh hai ((cau treo) OR (cau theo))*.