Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
hanh doi » thanh doi, hanh noi, hang doi
ban hanh » ban hang
so sach » so sanh, co sach, hoc sach
doi cua » dai cua, hoi cua
cam tuc » cam xuc, cam tu, dam thuc
hieu va » lieu va, hieu qua
bo sach » co sach, hoc sach
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sach) or (bo sach)) y nang x hoi. hieu va ((cam tuc) OR (nam thuc)) ban hanh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (bo sach)) y nang x hoi. hieu va ((cam tuc) OR (nam thuc)) ban hanh doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (bo sach)) y nang x hoi. hieu va ((cam tuc) OR (nam thuc)) ban hanh doi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (bo sach)) y nang x hoi. hieu va ((cam tuc) OR (nam thuc)) ban hanh doi cua tre*.