Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
qua cam » qua cham, qua cac, qua ca
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
cua tre » cua te, cuu tre, cua triet
ha hoi » hoa hoi, ha noi, xa hoi
vi cua » vai cua, di 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 ((ky lang) OR (ky tang)) ha hoi. hieu qua cam xuc ((va hanh) or (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky lang) OR (ky tang)) ha hoi. hieu qua cam xuc ((va hanh) OR (va danh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ky lang) OR (ky tang)) ha hoi. hieu qua cam xuc ((va hanh) or (va danh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky lang) OR (ky tang)) ha hoi. hieu qua cam xuc ((va hanh) or (va danh)) vi cua tre*.