Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
cua triet » cua viet, su triet, va triet
nuoc van » nuoc va, nuoc san, luoc van
van dang » van dong, van dung, van nang
dang tai » dang thai, dung tai, hang tai
sach ky » sac ky, sach y, sach ty
van cac » van hac, van cau, dan cac
van bac » van ban, van bao, van hac
tai cua » thai cua, tai cuc, tri cua
x hoi » xa hoi, o hoi, 5 hoi

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 nang ((x hoi) OR (x ho)). thien ((van cac) or (van bac)) nuoc van dang tai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang ((x hoi) OR (x ho)). thien ((van cac) OR (van bac)) nuoc van dang tai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang ((x hoi) OR (x ho)). thien ((van cac) or (van bac)) nuoc van dang tai cua triet".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang ((x hoi) OR (x ho)). thien ((van cac) or (van bac)) nuoc van dang tai cua triet*.