Perhaps you should try some spelling variations:
nang noi » nang doc
danh vai » danh sai, danh va, doanh van
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
noi hoi » noi doi, doi hoi, hoi hoi
hieu va » lieu va, hieu qua
thuc va » thuc dan, thuc day
vai su » va su, van su, lai su
va am » va lam, va cam

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang noi hoi. hieu va am ((thuc va) OR (thuc vat)) danh vai su triet~.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang noi hoi. hieu va am ((thuc va) or (thuc vat)) danh vai su triet*.