Perhaps you should try some spelling variations:
qua nhan » cua nhan, qua nhat, qua phan
nhan huu » phan huu, nhan thuc, nhan chua
su triet » su viet, su tien, ve triet
cua viet » ca viet, hoa viet, cua vat
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
han anh » phan anh, han danh, nhan anh
anh vi » hanh vi, anh va, anh ve

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 ((nang xa) or (nang x)) hoi. hieu qua nhan huu han anh vi ((su triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (nang x)) hoi. hieu qua nhan huu han anh vi ((su triet) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (nang x)) hoi. hieu qua nhan huu han anh vi ((su triet) or (cua viet))*.