Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
cau treo » cau tren, cau triet, cau trieu
danh hai » dang hai, lanh hai, manh hai
hieu van » hieu va, thien van, lieu va
mai hoi » mai khoi, dai hoi, lai hoi
sach ly » sach y, sach lo, sach ty
nam tuc » nam thuc, nam truc, nam tu
va danh » va dinh, va dan, va hanh
ly nang » ky nang, ly hang, ly vang
su sach » so sach, vu sach
ma hoi » xa hoi, ma hoa, me hoi
tuc va » thuc va, truc va, tuc xa

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