Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
van dinh » van minh, van dich, xuan dinh
cao hoi » cau hoi, co hoi, tao hoi
cao hoc » co hoc, cho hoc, chat hoc
va tham » van tham, va cham, va thanh
va dinh » va kinh, va tinh, vu dinh
dat cua » dai cua, day cua, mat cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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 y nang ((cao hoi) OR (cao hoc)). lieu va tham thuc ((va dinh) or (van dinh)) dat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((cao hoi) OR (cao hoc)). lieu va tham thuc ((va dinh) OR (van dinh)) dat cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ((cao hoi) OR (cao hoc)). lieu va tham thuc ((va dinh) or (van dinh)) dat cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ((cao hoi) OR (cao hoc)). lieu va tham thuc ((va dinh) or (van dinh)) dat cua tre*.