Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
sach ky » sach y, sach ty, sach kem
duc van » duc va, duc tan, duc manh
ve cham » va cham, ve chat, vu cham
cuu tre » cua tre, cau tren, cau treo
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky
vi cuu » vi luu, vinh cuu
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: su ((sach ky) or (sac ky)) nang xa hoi. hieu ((ve cai) or (ve cham)) duc van hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang xa hoi. hieu ((ve cai) OR (ve cham)) duc van hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sac ky)) nang xa hoi. hieu ((ve cai) or (ve cham)) duc van hanh vi cuu tre*.