Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
ky dang » ky nang, ky danh
xay hoi » xa hoi, cay phoi, gay thoi
tay hoi » tay ho, tao hoi, tay thai
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
anh via » anh va, anh bia, anh giao
ve cac » va cac, vien cac
cac lo » cac lop, cac co, cac bo
lo van » le van, vo van, so van
thiet » thieu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky dang ((xay hoi) or (tay hoi)). hieu ve cac lo van ((anh via) or (anh viet)) va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky dang ((xay hoi) OR (tay hoi)). hieu ve cac lo van ((anh via) OR (anh viet)) va thiet.
• Adding a wildcard symbol may retrieve word variants: thuat sach ky dang ((xay hoi) or (tay hoi)). hieu ve cac lo van ((anh via) or (anh viet)) va thiet*.