Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cau treo » cau theo, cau tren, cau triet
sach ky » sac ky, sach ty, sach kem
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc ((sach ky) or (sach y)) lang xa hoi. hieu ve pham duc van hanh vi ((cua tre) or (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc ((sach ky) OR (sach y)) lang xa hoi. hieu ve pham duc van hanh vi ((cua tre) OR (cau treo)).
• Adding a wildcard symbol may retrieve word variants: thuoc ((sach ky) or (sach y)) lang xa hoi. hieu ve pham duc van hanh vi ((cua tre) or (cau treo))*.