Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh va » thanh van, hanh va, thanh ha
cua tre » cua te, cua triet, dua tren
duc van » duc va, duc tan, duc manh
sach ky » sac ky, sach y, sach kem
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
cuu tre » cau tren, cau treo
x hoi » xa hoi, o hoi, x ho

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 ky) OR (sach ty)) nang x hoi. hieu va cac duc van thanh va ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang x hoi. hieu va cac duc van thanh va ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang x hoi. hieu va cac duc van thanh va ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang x hoi. hieu va cac duc van thanh va ((cua tre) or (cuu tre))*.