Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
thanh ve » hanh ve, thanh va, thanh vien
dang xay » dang van, van xay
tu sach » thu sach, su sach, te sach
cuu tre » cua tre, cau tren, cau treo
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 ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
ca tren » cau tren, cu tren, la tren

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 ty ((nang xa) or (dang xay)) hoi. hieu van cam duc van thanh ve ((cuu tre) or (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (dang xay)) hoi. hieu van cam duc van thanh ve ((cuu tre) OR (ca tren)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (dang xay)) hoi. hieu van cam duc van thanh ve ((cuu tre) or (ca tren))*.