Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
thuc van » thuc vat, thuc dan, thuc va
su triet » su viet, su tien
van hanh » van thanh, ban hanh, van anh
ve triet » va trien
hieu va » lieu va, hieu qua
va nham » va cham, va tham, va nha
sach tu » sach thu, cach tu, sach ty
dang ma » dang mau, dang mam, dang mat
hanh ki » hanh vi, hanh ky, hanh kien
tu dang » thu dang, tu dong, su dang
tu sach » thu sach, su sach, te sach
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: tu sach tu dang ma hoi. hieu va nham thuc van hanh ki ((su triet) OR (ve triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu dang ma hoi. hieu va nham thuc van hanh ki ((su triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach tu dang ma hoi. hieu va nham thuc van hanh ki ((su triet) OR (ve triet))*.