Perhaps you should try some spelling variations:
sach han » sach tham, sach danh, sach nang
hieu van » hieu va, thien van, lieu va
nam xuc » cam xuc, nam xua, nam thuc
va hanh » van hanh, va thanh, va danh
su tien » su kien, su hien, tu tieng
ma hoi » mai hoi, ma hoa, me hoi
xuc va » duc va, tuc va, luc va
vi su » va su, ve su, ki 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 han) or (cach mang)) tang ((ma hoi) OR (xa hoi)). hieu van nam xuc va hanh vi su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach han) OR (cach mang)) tang ((ma hoi) OR (xa hoi)). hieu van nam xuc va hanh vi su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach han) or (cach mang)) tang ((ma hoi) OR (xa hoi)). hieu van nam xuc va hanh vi su tien".
• Adding a wildcard symbol may retrieve word variants: su ((sach han) or (cach mang)) tang ((ma hoi) OR (xa hoi)). hieu van nam xuc va hanh vi su tien*.