Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, can thuc
te sach » toc sach
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
cam thu » nam thu, cac thu, ca thu
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
ty hang » ly hang, ty xang, thi hang
ty ang » ty xang, ty anh
di cuu » di cau, di cua, dinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ty ang) or (ty hang)) xa hoi. hieu va ((cam thuc) OR (cam thu)) va hanh di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty ang) OR (ty hang)) xa hoi. hieu va ((cam thuc) OR (cam thu)) va hanh di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ty ang) or (ty hang)) xa hoi. hieu va ((cam thuc) OR (cam thu)) va hanh di cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ty ang) or (ty hang)) xa hoi. hieu va ((cam thuc) OR (cam thu)) va hanh di cuu tre*.