Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cau tuc » cau truc, cau luc, cau phuc
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cau tu » dau tu, cau truc
di hoa » dai hoa, doi hoa, do hoa
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 nang x hoi. ((hieu van) or (hieu va)) ((cau tuc) OR (cau tu)) va hanh di hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((hieu van) OR (hieu va)) ((cau tuc) OR (cau tu)) va hanh di hoa viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((hieu van) or (hieu va)) ((cau tuc) OR (cau tu)) va hanh di hoa viet*".