Perhaps you should try some spelling variations:
va trinh » van trinh, va tinh, lap trinh
trinh he » trinh han, trinh hoa, trinh thi
su sach » so sach, vu sach
ky lang » ky dang, ky tang, tay lang
van cac » van hac, van bac, dan cac
van cau » van dau, van hau, van chat
cua tre » cua te, cuu tre, cua triet
loc va » hoc va, luc va
he cua » le cua, hu 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 ((ky lang) OR (ky nang)) xa hoi. hieu ((van cac) OR (van cau)) loc va trinh he cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky lang) OR (ky nang)) xa hoi. hieu ((van cac) or (van cau)) loc va trinh he cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky lang) OR (ky nang)) xa hoi. hieu ((van cac) or (van cau)) loc va trinh he cua tre*.