Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
phan duc » pham duc, phan tu, phan dau
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
ve phan » va phan, ke phan, ve phat
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu ve phan duc va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu ve phan duc va hanh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu ve phan duc va hanh vai cua tre*".