Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
va hanh » van hanh, va danh, ban hanh
qua cam » qua cham, qua cac, qua ca
cam luc » cam xuc, cau luc
vu dang » su dang, vu quang, cua dang
vu nang » vuc nang, va nang, v nang
cua tre » cua te, cuu tre, cua triet
de cua » le cua, te cua, dieu cua

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