Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
cau triet » cau trieu, su triet, cua triet
cay phoi » cap phoi, tay hoi, cay cho
hieu van » hieu va, thien van, lieu va
ky dang » ky danh
hanh va » hang va, hanh vi
van cam » van nam, van lam, van cau
loc va » hoc va, luc va
va cau » van cau, va cac, va dau

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) OR (ky nang)) cay phoi. hieu van cam ((duc va) or (loc va)) hanh va cau triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ((ky dang) OR (ky nang)) cay phoi. hieu van cam ((duc va) OR (loc va)) hanh va cau triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ((ky dang) OR (ky nang)) cay phoi. hieu van cam ((duc va) or (loc va)) hanh va cau triet".
• Adding a wildcard symbol may retrieve word variants: thuat sach ((ky dang) OR (ky nang)) cay phoi. hieu van cam ((duc va) or (loc va)) hanh va cau triet*.