Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nang tri » nang tai, lang tri, nang thi
sach ky » sac ky, sach y, sach ty
van bac » van bao, van hac, van bau
dan bac » dan ba, dong bac, gian bac
va nang » van nang, da nang, cam nang
cua tre » cua te, cuu tre, cua triet
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: thu sach ky nang x hoi. thien ((((van bac) OR (dan bac))) or (van ban)) nuoc va nang tri cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang x hoi. thien ((((van bac) OR (dan bac))) OR (van ban)) nuoc va nang tri cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang x hoi. thien ((((van bac) OR (dan bac))) or (van ban)) nuoc va nang tri cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang x hoi. thien ((((van bac) OR (dan bac))) or (van ban)) nuoc va nang tri cua tre*.