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
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
tang xa » trang xa, tang ma, tang ha
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: tu sach ky ((tang 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: tu sach ky ((tang 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: tu sach ky ((tang xa) or (lang xa)) hoi. hieu ve cham duc van hanh vi ((cua tre) or (cau tren))*.