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
bo sach » co sach, hoc sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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