Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
su triet » su viet, su tien, ve triet
thu sach » thuat sach, thuoc sach, thu hoach
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
thu dang » thu hang, thu bang, thu dong
hanh ki » hanh vi, hanh ky, hanh kien
va nham » va cham, va tham, va nha
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
tu dang » tu dong, su dang, vu dang
mam hoi » mam hoai, nam hoi, mai hoi
ki su » ky su

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 (thu sach)) ((tu dang) OR (thu dang)) mam hoi. hieu va nham thuc van hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ((tu dang) OR (thu dang)) mam hoi. hieu va nham thuc van hanh ki su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ((tu dang) OR (thu dang)) mam hoi. hieu va nham thuc van hanh ki su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ((tu dang) OR (thu dang)) mam hoi. hieu va nham thuc van hanh ki su triet*.