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
tu sach » thu sach, te sach, tu cach
ma hanh » va hanh, da hanh, na hanh
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
vi cuu » vi luu, vinh cuu
x hoi » xa hoi, o hoi, x ho

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 (su sach)) ky nang x hoi. ((hieu ve) or (thien van)) nha thuoc ma hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang x hoi. ((hieu ve) OR (thien van)) nha thuoc ma hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang x hoi. ((hieu ve) or (thien van)) nha thuoc ma hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang x hoi. ((hieu ve) or (thien van)) nha thuoc ma hanh vi cuu tre*.