Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
cuu tre » cau tren, cau treo
va hanh » van hanh, va thanh, va danh
nam loc » nam lo, nam moc, nam soc
tu sach » thu sach, su sach, te sach
tang ma » mang may, tang van
tang xa » trang xa, lang xa, tang ha
cua tre » cua te, cua triet, dua tren
loc va » hoc va, luc va

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 (tang ma)) hoi. hieu van nam loc va hanh vi ((cuu tre) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((tang xa) OR (tang ma)) hoi. hieu van nam loc va hanh vi ((cuu tre) OR (cua tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((tang xa) or (tang ma)) hoi. hieu van nam loc va hanh vi ((cuu tre) or (cua tre))*.