Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hieu cua » hieu qua, dieu cua, bieu cua
van tuan » van quan, van ban, anh tuan
tuan ve » tuan le, quan ve, luan ve
cau luc » cau truc, cau phuc
sach ky » sac ky, sach y, sach ty
te sach » toc sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cac luc » coc luc, cac nuoc, cac cuoc
ve va » ve van, te va, ke va

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 ((nang xa) or (nang ma)) hoi. hieu cua ((cac luc) OR (cau luc)) van tuan ve va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (nang ma)) hoi. hieu cua ((cac luc) OR (cau luc)) van tuan ve va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang xa) or (nang ma)) hoi. hieu cua ((cac luc) OR (cau luc)) van tuan ve va triet".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (nang ma)) hoi. hieu cua ((cac luc) OR (cau luc)) van tuan ve va triet*.