Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
ban benh » san benh, ba benh, ban banh
hieu van » thien van, lieu va, hieu ve
cam duc » cam xuc, cao duc, pham duc
benh di » benh dai, ben di, benh da
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
di cua » dai cua, doi cua, de cua

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 (thuoc sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) cam duc ban benh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) cam duc ban benh di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuoc sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) cam duc ban benh di cua tre*".