Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
van hanh » van thanh, ban hanh, van anh
cham duc » pham duc, cham soc, pham duy
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
bo sach » co sach, hoc sach
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
ve cham » va cham, ve chat, vu cham

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach ky ((nang xa) or (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: bo sach ky ((nang xa) OR (lang xa)) hoi. hieu ve cham duc van hanh vi ((cua tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: bo sach ky ((nang xa) or (lang xa)) hoi. hieu ve cham duc van hanh vi ((cua tre) or (cau tren))*.