Perhaps you should try some spelling variations:
thanh vi » thanh va, thanh ve, nhanh vi
hieu van » hieu va, thien van, lieu va
toc sac » toc sach, toc san, hoc sach
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
van cam » van nam, van lam, van cau
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
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 sac ky ((nang xa) or (nang ma)) hoi. hieu van cam duc van ((thanh vi) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sac ky ((nang xa) OR (nang ma)) hoi. hieu van cam duc van ((thanh vi) OR (hanh vi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sac ky ((nang xa) or (nang ma)) hoi. hieu van cam duc van ((thanh vi) or (hanh vi)) cua tre*.