Perhaps you should try some spelling variations:
thieu hang » thieu khang, thieu quang, thu hang
thi hang » thi hanh, thi nang, thi hong
va trinh » van trinh, va tinh, lap trinh
trinh te » trinh tu, trinh he, trinh ke
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
cua tre » cua te, cuu tre, cua triet
ca hoi » cua hoi, xa hoi, co hoi
te cua » tue cua, le cua, de cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((thieu hang) OR (thi hang)) ((ca hoi) OR (cau hoi)). hieu va cac duc va trinh te cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((thieu hang) or (thi hang)) ((ca hoi) OR (cau hoi)). hieu va cac duc va trinh te cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach ((thieu hang) or (thi hang)) ((ca hoi) OR (cau hoi)). hieu va cac duc va trinh te cua tre*.