Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, pham thuc
thu sach » thuat sach, thuoc sach, thu hoach
dinh vai » dinh van, dinh vi, dinh va
van dinh » van minh, van dich, va dinh
lang mai » lang dai, lang hai, lang man
nham thu » nam thu, pham thu, nhan thuc
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky lang » ky nang, ky dang, ky tang
tu sach » su sach, te sach, tu cach
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (tu sach)) ky lang mai hoi. hieu ve ((nham thuc) OR (nham thu)) van dinh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ky lang mai hoi. hieu ve ((nham thuc) OR (nham thu)) van dinh vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (tu sach)) ky lang mai hoi. hieu ve ((nham thuc) OR (nham thu)) van dinh vai cua te".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ky lang mai hoi. hieu ve ((nham thuc) OR (nham thu)) van dinh vai cua te*.