Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
hieu van » hieu va, thien van, lieu va
lang xa » dang xay, lang van
lang ha » long ha
sach ky » sac ky, sach y, sach ty
van lam » van nam
lam duc » lam duoc, pham duc, nam duoc
dan vai » dan va, dan vat, den vai
dan tai » van tai, dan thi, han tai
te sach » toc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((lang xa) OR (lang ha)) hoi. hieu van lam duc va ((dan vai) or (dan tai)) cau theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((lang xa) OR (lang ha)) hoi. hieu van lam duc va ((dan vai) OR (dan tai)) cau theo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((lang xa) OR (lang ha)) hoi. hieu van lam duc va ((dan vai) or (dan tai)) cau theo".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((lang xa) OR (lang ha)) hoi. hieu van lam duc va ((dan vai) or (dan tai)) cau theo*.