Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van pham » san pham, van phat, van tham
van phan » van phong, van thanh, luan phan
dinh nam » dinh lam, dinh van, dinh ba
tinh nam » tinh lao, tinh va
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet

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 nang xa hoi. hieu ((van pham) OR (van phan)) duc va ((dinh nam) or (tinh nam)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu ((van pham) OR (van phan)) duc va ((dinh nam) OR (tinh nam)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. hieu ((van pham) OR (van phan)) duc va ((dinh nam) or (tinh nam)) cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu ((van pham) OR (van phan)) duc va ((dinh nam) or (tinh nam)) cua tre*.