Perhaps you should try some spelling variations:
thieu bien » thieu nien, tieu bieu, hien bien
cua viet » ca viet, hoa viet, cua vat
van hanh » van thanh, ban hanh, van anh
bien cac » vien cac, dien cac, bien ca
vuc van » duc van, luc van, thuc van
cac vuc » cac nuoc, cac vung, cac cuoc
sach ky » sach y, sach ty, sach kem
nang xa » lang xa, nang ma, mang xa
sac ky » cac ky, sai ky
vi cua » vai cua, di cua

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) OR (sac ky)) ((nang xa) or (nang x)) hoi. thieu bien cac vuc van hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) ((nang xa) OR (nang x)) hoi. thieu bien cac vuc van hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) ((nang xa) or (nang x)) hoi. thieu bien cac vuc van hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sac ky)) ((nang xa) or (nang x)) hoi. thieu bien cac vuc van hanh vi cua viet*.