Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
ve cham » va cham, ve chat, vu cham
sach ky » sac ky, sach y, sach kem
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
vi cua » vai cua, di cua
ve cai » va cai, ve cac, ve tai

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) or (sach ty)) nang xa hoi. hieu ((ve cai) or (ve cham)) duc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang xa hoi. hieu ((ve cai) OR (ve cham)) duc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach ty)) nang xa hoi. hieu ((ve cai) or (ve cham)) duc van hanh vi cua tre*.