Perhaps you should try some spelling variations:
tan hanh » tan thanh, tang hanh, toan hanh
tang van » dang van, hoang van, trong van
te sach » toc sach
cua tuc » cua tu, cua thuoc, luat tuc
hanh di » hanh vi, hanh de, hang di
cac duc » cac du, cao duc, cac dac
sach lo » sach dao, sach doi, sach hoi
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
cua duc » cua nuoc, cua quoc
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach lo ((nang ma) or (tang van)) hoi. hieu ve cac duc tan hanh di ((cua tuc) OR (cua duc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach lo ((nang ma) OR (tang van)) hoi. hieu ve cac duc tan hanh di ((cua tuc) OR (cua duc))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach lo ((nang ma) or (tang van)) hoi. hieu ve cac duc tan hanh di ((cua tuc) OR (cua duc))*".