Perhaps you should try some spelling variations:
cach thuc » anh thuc, cac thu
cuon sach » duong sach, cuoc cach, nuoc sach
su triet » su viet, ve triet
hanh lai » hanh lam, hanh tai, thanh lap
co sach » bo sach, hoc sach
xa hanh » xa thanh, xa khanh, va hanh
thuc xa » thuc xay, tuc xa, thuc va
ve cach » va cach, ve cac, ve canh
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
su tien » su kien, su hien, tu tieng

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((co sach) or (cuon sach)) ty nang ma hoa. hieu ve cach thuc xa hanh lai ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((co sach) OR (cuon sach)) ty nang ma hoa. hieu ve cach thuc xa hanh lai ((su triet) OR (su tien)).
• Adding a wildcard symbol may retrieve word variants: ((co sach) or (cuon sach)) ty nang ma hoa. hieu ve cach thuc xa hanh lai ((su triet) or (su tien))*.