Perhaps you should try some spelling variations:
sach ky » sach y, sach ty, sach kem
lai hoa » loai hoc
va hanh » van hanh, va thanh, va danh
cac tuc » cac toc, cac tu, cac tac
dai hoa » dai khoa, dai hoc, dai hoi
hieu ve » hieu va, hieu van
tuc va » thuc va, truc va, tuc xa
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho

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 x hoi. hieu ve cac tuc va hanh ((lai hoa) OR (dai hoa)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang x hoi. hieu ve cac tuc va hanh ((lai hoa) OR (dai hoa)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) nang x hoi. hieu ve cac tuc va hanh ((lai hoa) OR (dai hoa)) viet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang x hoi. hieu ve cac tuc va hanh ((lai hoa) OR (dai hoa)) viet*.