Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
sach ky » sac ky, sach y, sach ty
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
mang xa » lang xa, mang may, dang xay
cuu tre » cua tre, cau treo
tu sach » thu sach, su sach, te sach

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