Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cam thuc » am thuc, nam thuc, cam thu
hanh dai » hanh tai, hanh dao, vanh dai
tu sach » thu sach, su sach, te sach
co sach » bo sach, cuon sach, hoc sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
ve cam » ve cham, ve cac, va cam

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) or (co sach)) ky ((nang xa) OR (lang xa)) hoi. hieu ve cam thuc va hanh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (co sach)) ky ((nang xa) OR (lang xa)) hoi. hieu ve cam thuc va hanh dai cua triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (co sach)) ky ((nang xa) OR (lang xa)) hoi. hieu ve cam thuc va hanh dai cua triet*".