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
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
sach ty » sach y, sach tu, sach thu
vu sach » vu bach, su sach, vu khach
nang ma » sang ma, nang cao, mang may
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
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: vu sach ty ((nang ma) OR (tang ma)) hoi. hieu ve cam thuc va hanh vi ((cua triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty ((nang ma) OR (tang ma)) hoi. hieu ve cam thuc va hanh vi ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty ((nang ma) OR (tang ma)) hoi. hieu ve cam thuc va hanh vi ((cua triet) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: vu sach ty ((nang ma) OR (tang ma)) hoi. hieu ve cam thuc va hanh vi ((cua triet) or (cua viet))*.