Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
toc sach » hoc sach, doc sach, thuoc sach
van cam » van nam, van cau, van dam
tuc van » thuc van, truc van, tuc va
van lam » van nam
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
va viet » hoa viet, san viet, mai viet
vi va » vi van, vai va, vu va

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) OR (toc sach)) ky dang xa hoi. hieu ((van cam) or (van lam)) tuc van hanh vi va viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky dang xa hoi. hieu ((van cam) OR (van lam)) tuc van hanh vi va viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky dang xa hoi. hieu ((van cam) or (van lam)) tuc van hanh vi va viet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky dang xa hoi. hieu ((van cam) or (van lam)) tuc van hanh vi va viet*.