Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
toc sach » hoc sach, doc sach, thuoc sach
van hanh » ban hanh, van anh, van ban
cac xuc » cam xuc, cac nuoc, chat xuc
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
tang ma » tang van
ve cac » va cac, vien cac
cua tu » cua tuc, cua su, cua cu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ty ((tang ma) OR (mang may)) hoi. hieu ve cac xuc ((van hanh) or (van thanh)) dai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty ((tang ma) OR (mang may)) hoi. hieu ve cac xuc ((van hanh) OR (van thanh)) dai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty ((tang ma) OR (mang may)) hoi. hieu ve cac xuc ((van hanh) or (van thanh)) dai cua tu".
• Adding a wildcard symbol may retrieve word variants: toc sach ty ((tang ma) OR (mang may)) hoi. hieu ve cac xuc ((van hanh) or (van thanh)) dai cua tu*.