Perhaps you should try some spelling variations:
nha thuoc » nha nuoc, nhan thuc, nha hoc
thien van » thi van
thuoc ma » hoc ma, duoc ma
hieu van » lieu va, hieu ve
tu sach » thu sach, su sach, te sach
ma hanh » va hanh, da hanh, na hanh
luy tre » luyen tre
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nang o » nang co, nang ho, nang ro
vi luy » vi lua, vi luu
o hoi » co hoi, o hoc, o hai

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 o hoi. ((((hieu van) or (hieu va))) or (thien van)) nha thuoc ma hanh vi luy tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang o hoi. ((((hieu van) OR (hieu va))) OR (thien van)) nha thuoc ma hanh vi luy tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hoi. ((((hieu van) or (hieu va))) or (thien van)) nha thuoc ma hanh vi luy tre*.