Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
toc sac » toc sach, toc san, hoc sach
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
vai cau » va cau, van cau, vai cac
sac ky » cac ky, sai ky
va nam » ha nam, va nay
va dan » ca dan, va dao, va dap
va dau » va dao

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

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