Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
thanh vi » hanh vi, thanh va, thanh ve
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
van cam » van nam, van lam, van cau
sach ky » sach y, sach ty, sach kem
lang xa » lang ha, dang xay, lang van
cuu tre » cua tre, cau tren, cau treo
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach ky) OR (sac ky)) lang xa hoi. hieu van cam duc van thanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ky) OR (sac ky)) lang xa hoi. hieu van cam duc van thanh vi ((dua tren) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ky) OR (sac ky)) lang xa hoi. hieu van cam duc van thanh vi ((dua tren) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: toc ((sach ky) OR (sac ky)) lang xa hoi. hieu van cam duc van thanh vi ((dua tren) or (cuu tre))*.