Perhaps you should try some spelling variations:
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
toc sach » hoc sach, doc sach, thuoc sach
tinh cua » trinh cua, sinh cua, tinh chat
sach ky » sac ky, sach y, sach ty
ve chat » va chat, van chat
hieu ve » hieu va, hieu van
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
ha hoi » hoa hoi, ha noi, va hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky lang ((ha hoi) OR (xa hoi)). hieu ve chat ((xuc va) or (thuc vat)) hanh tinh cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang ((ha hoi) OR (xa hoi)). hieu ve chat ((xuc va) OR (thuc vat)) hanh tinh cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky lang ((ha hoi) OR (xa hoi)). hieu ve chat ((xuc va) or (thuc vat)) hanh tinh cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang ((ha hoi) OR (xa hoi)). hieu ve chat ((xuc va) or (thuc vat)) hanh tinh cua tre*.