Perhaps you should try some spelling variations:
sach tham » sach nha
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
cam luc » cam xuc
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may

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 tham ((nang ma) OR (tang ma)) hoi. hieu va ((cam luc) or (cau luc)) va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tham ((nang ma) OR (tang ma)) hoi. hieu va ((cam luc) OR (cau luc)) va hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tham ((nang ma) OR (tang ma)) hoi. hieu va ((cam luc) or (cau luc)) va hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach tham ((nang ma) OR (tang ma)) hoi. hieu va ((cam luc) or (cau luc)) va hanh vai cua tre*.