Perhaps you should try some spelling variations:
danh kien » dinh kien, danh viet, linh kien
toc sach » hoc sach, doc sach, thuoc sach
cam thuc » nam thuc, cam thu, can thuc
nang xa » nang x, lang xa, nang ma
hanh de » hanh ve, hanh kem
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 xa hoi. hieu qua ((cam thuc) OR (am thuc)) va ((danh kien) or (hanh de)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang xa hoi. hieu qua ((cam thuc) OR (am thuc)) va ((danh kien) OR (hanh de)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang xa hoi. hieu qua ((cam thuc) OR (am thuc)) va ((danh kien) or (hanh de)) cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang xa hoi. hieu qua ((cam thuc) OR (am thuc)) va ((danh kien) or (hanh de)) cua tre*.