Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nang xay » dang xay, nganh xay, nang xuan
sach ky » sac ky, sach ty, sach kem
va hanh » van hanh, va thanh, va danh
cam loc » cam lo
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
xay hoi » xa hoi, tay hoi, cay phoi
loc va » hoc va, luc va
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: su ((sach ky) OR (sach y)) nang xay hoi. ((hieu ve) or (hieu van)) cam loc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) nang xay hoi. ((hieu ve) OR (hieu van)) cam loc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach y)) nang xay hoi. ((hieu ve) or (hieu van)) cam loc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sach y)) nang xay hoi. ((hieu ve) or (hieu van)) cam loc va hanh vi cua tre*.