Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
ban benh » san benh, ba benh, ban banh
duoc ban » duc ban, quoc ban, buoc ban
lam duoc » nam duoc, luat duoc, lam thuoc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
van lam » van nam
vi va » vai va, vu va, bi va

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 ky ((nang ma) or (nang x)) hoi. hieu van lam duoc ban benh ((vi va) OR (vi van)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (nang x)) hoi. hieu van lam duoc ban benh ((vi va) OR (vi van)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang ma) or (nang x)) hoi. hieu van lam duoc ban benh ((vi va) OR (vi van)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) or (nang x)) hoi. hieu van lam duoc ban benh ((vi va) OR (vi van)) triet*.