Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hien bach » vien bach, hien hanh, dien sach
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
bo sach » co sach, hoc sach
lang ha » long ha
lang xa » dang xay, lang van
vi cua » vai cua, di cua
cua su » qua su

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 ((lang xa) OR (lang ha)) hoi. bieu ((hien bach) or (thien hach)) nuoc va hanh vi cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach ky ((lang xa) OR (lang ha)) hoi. bieu ((hien bach) OR (thien hach)) nuoc va hanh vi cua su*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach ky ((lang xa) OR (lang ha)) hoi. bieu ((hien bach) or (thien hach)) nuoc va hanh vi cua su*".