Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
thanh va » thanh van, hanh va, thanh ha
thanh vi » hanh vi, thanh ve, nhanh vi
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
cac loc » cac lop, cac toc, cac hoc
y lang » _ lang, tay lang, yen lang
loc va » hoc va, luc va
o lang » hoa lang, hoi lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((y lang) OR (o lang)) xa hoi. hieu va cac loc va ((thanh vi) or (thanh va)) cau theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y lang) OR (o lang)) xa hoi. hieu va cac loc va ((thanh vi) OR (thanh va)) cau theo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y lang) OR (o lang)) xa hoi. hieu va cac loc va ((thanh vi) or (thanh va)) cau theo".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y lang) OR (o lang)) xa hoi. hieu va cac loc va ((thanh vi) or (thanh va)) cau theo*.