Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cham duc » pham duc, cham soc, pham duy
cau tren » cu tren, dau tren, ca tren
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
ve cham » va cham, ve chat, vu cham
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: thuoc ((sac ky) or (sach y)) lang xa hoi. hieu ve cham duc van hanh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc ((sac ky) OR (sach y)) lang xa hoi. hieu ve cham duc van hanh vi ((cua tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: thuoc ((sac ky) or (sach y)) lang xa hoi. hieu ve cham duc van hanh vi ((cua tre) or (cau tren))*.