Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
su triet » su viet, su tien, ve triet
dang mam » dang nam, dang mau, dang mat
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
hanh ki » hanh vi, hanh ky, hanh kien
va nham » va cham, va tham, va nha
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, tu cach
dang ma » dang mau, dang mat, tang ma
te sach » toc sach
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 (te sach)) vu ((dang ma) OR (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 (te sach)) vu ((dang ma) OR (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 (te sach)) vu ((dang ma) OR (dang mam)) hoi. hieu va nham thuc van hanh ki su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) vu ((dang ma) OR (dang mam)) hoi. hieu va nham thuc van hanh ki su triet*.