Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
danh dai » danh dau, danh di, danh sai
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
van bac » van ban, van bao, van bau
dan bac » dan ba, dong bac, gian bac
van hac » van hoc, van ha, van hai
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ty nang x hoi. hieu ((((van bac) OR (dan bac))) or (van hac)) thuc va danh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ty nang x hoi. hieu ((((van bac) OR (dan bac))) OR (van hac)) thuc va danh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ty nang x hoi. hieu ((((van bac) OR (dan bac))) or (van hac)) thuc va danh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ty nang x hoi. hieu ((((van bac) OR (dan bac))) or (van hac)) thuc va danh dai cua tre*.