Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh dai » hanh tai, hanh dao, vanh dai
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
cau tuc » cau truc, cau tu, cau phuc
sach ky » sac ky, sach ty, sach kem
tang xa » trang xa, tang ma, lang xa
cua tre » cua te, cuu tre, cua triet

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