Perhaps you should try some spelling variations:
danh doi » danh di, thanh doi, dung doi
dia danh » dia ban, gia dinh
sang tao » hang tai
hieu van » hieu va, thien van, lieu va
cac tuc » cac toc, cac tu, cac nuoc
doi cua » dai cua, hoi cua
cac tac » cac toc, cac bac, cac dac
sach ky » sach y, sach ty, sach kem
tao hoi » tao khoi, tao boi, tay hoi
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

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)) sang tao hoi. hieu van ((cac tuc) OR (cac tac)) dia danh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) sang tao hoi. hieu van ((cac tuc) OR (cac tac)) dia danh doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) sang tao hoi. hieu van ((cac tuc) OR (cac tac)) dia danh doi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) sang tao hoi. hieu van ((cac tuc) OR (cac tac)) dia danh doi cua tre*.