Perhaps you should try some spelling variations:
su triet » su viet, su tien
hang cau » hang dau, hang ca, nhung cau
hieu van » hieu va, thien van, lieu va
ve triet » va trien
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty hang » ly hang, ty xang, thi hang
tuc va » thuc va, truc va, tuc xa
xuc va » duc va, luc va, xac va

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 ty hang cau hoi. hieu van nam ((xuc va) or (tuc va)) hanh vi ((ve triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty hang cau hoi. hieu van nam ((xuc va) OR (tuc va)) hanh vi ((ve triet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ty hang cau hoi. hieu van nam ((xuc va) or (tuc va)) hanh vi ((ve triet) or (su triet))*.