Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
su triet » su viet, su tien
vanh dai » van dai, vanh tai, lanh dao
ve triet » va trien
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
thuc va » thuc vat, thuc dan, thuc day
va vanh » va van, va danh, va hanh
nang ma » tang ma, sang ma, nang cao
te sach » toc sach
ma hoi » mai hoi, xa hoi, ma hoa
sach 2 » sach y
2 nang » v nang

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 2 nang ma hoi. hieu ve cham thuc va vanh dai ((su triet) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach 2 nang ma hoi. hieu ve cham thuc va vanh dai ((su triet) OR (ve triet)).
• Adding a wildcard symbol may retrieve word variants: te sach 2 nang ma hoi. hieu ve cham thuc va vanh dai ((su triet) or (ve triet))*.