Perhaps you should try some spelling variations:
lang van » dang van, tang van, hoang van
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
tang ma » mang may, tang van
qua cai » qua hai, qua cac, qua ca
cai duc » cao duc, mai duc, hoai duc
duc van » duc va, duc tan, duc manh
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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 y ((tang ma) or (lang van)) hoi. hieu qua cai duc van hanh vi ((cua tu) OR (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((tang ma) OR (lang van)) hoi. hieu qua cai duc van hanh vi ((cua tu) OR (cua su))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((tang ma) or (lang van)) hoi. hieu qua cai duc van hanh vi ((cua tu) OR (cua su))*".