Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cam thuc » am thuc, nam thuc, cam thu
nang xa » nang x, lang xa, nang ma
qua cam » qua cham, qua cac, qua ca
thuc va » thuc vat, thuc dan, thuc day
danh di » danh du, xanh di, danh dien
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 va ((danh di) 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 va ((danh di) OR (hanh de)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y nang xa hoi. hieu qua cam thuc va ((danh di) or (hanh de)) cua tre*.