Perhaps you should try some spelling variations:
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
cam thuc » am thuc, nam thuc, cam thu
sach nay » sach hay, sach vay, sach nang
sach tay » xach tay, sach hay, sach tai
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
ve cam » ve cham, ve cac, va cam
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach tay) OR (sach nay)) tang ma hoi. hieu ve cam thuc va danh vi ((cua triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach tay) OR (sach nay)) tang ma hoi. hieu ve cam thuc va danh vi ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach tay) OR (sach nay)) tang ma hoi. hieu ve cam thuc va danh vi ((cua triet) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: so ((sach tay) OR (sach nay)) tang ma hoi. hieu ve cam thuc va danh vi ((cua triet) or (cua viet))*.