Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thu sach » tu sach, thuoc sach, thu hoach
dang hai » dang khai, hang hai, dung hai
hieu van » hieu va, thien van, lieu va
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
van cam » van nam, van lam, van cau
xuc ban » duc ban, cuc ban, quoc ban
duc van » duc va, duc tan, duc manh
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet

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 (thuat sach)) ky tang xa hoi. hieu van cam ((xuc ban) or (duc van)) dang hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuat sach)) ky tang xa hoi. hieu van cam ((xuc ban) OR (duc van)) dang hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuat sach)) ky tang xa hoi. hieu van cam ((xuc ban) or (duc van)) dang hai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuat sach)) ky tang xa hoi. hieu van cam ((xuc ban) or (duc van)) dang hai cua tre*.