Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cau tren » cu tren, dau tren, ca tren
dang xay » dang van, van xay
va hanh » van hanh, va thanh, va danh
cam duc » cam xuc, cao duc, pham duc
van cam » van nam, van lam, van cau
te sach » toc sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, lang van
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: te sach ky ((lang xa) OR (dang xay)) hoi. hieu van cam duc va hanh vi ((cau tren) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((lang xa) OR (dang xay)) hoi. hieu van cam duc va hanh vi ((cau tren) OR (cua tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((lang xa) OR (dang xay)) hoi. hieu van cam duc va hanh vi ((cau tren) or (cua tre))".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((lang xa) OR (dang xay)) hoi. hieu van cam duc va hanh vi ((cau tren) or (cua tre))*.