Perhaps you should try some spelling variations:
cam thuc » am thuc, cam thu, can thuc
nam thuc » nam thuoc, am thuc, nam thu
danh lai » danh sai, gianh lai, dinh lam
chau tre » chay tren, chau tho, cau tra
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
cho tre » cho thue, khoe tre

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang xa hoi. hieu va ((cam thuc) or (nam thuc)) va danh lai ((chau tre) OR (cho tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu va ((cam thuc) OR (nam thuc)) va danh lai ((chau tre) OR (cho tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu va ((cam thuc) or (nam thuc)) va danh lai ((chau tre) OR (cho tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu va ((cam thuc) or (nam thuc)) va danh lai ((chau tre) OR (cho tre))*.