Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
va thanh » gia thanh, ban thanh, va tinh
vien cac » vien bach, vien dai, vien da
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, va hanh
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
ve cac » va cac

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 ky tang xa hoi. hieu ((ve cac) OR (vien cac)) thuc ((va danh) or (va thanh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky tang xa hoi. hieu ((ve cac) OR (vien cac)) thuc ((va danh) OR (va thanh)) dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky tang xa hoi. hieu ((ve cac) OR (vien cac)) thuc ((va danh) or (va thanh)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky tang xa hoi. hieu ((ve cac) OR (vien cac)) thuc ((va danh) or (va thanh)) dai cua tre*.