Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
qua tham » qua cham, qua than, qua thanh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
xay hoi » tay hoi, cay phoi, gay thoi
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vi su » va su, ve su, oi su
ki su » ky su

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((xay hoi) OR (xa hoi)). hieu qua tham thuc va hanh ((vi su) OR (ki su)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((xay hoi) or (xa hoi)). hieu qua tham thuc va hanh ((vi su) OR (ki su)) triet~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((xay hoi) or (xa hoi)). hieu qua tham thuc va hanh ((vi su) OR (ki su)) triet*.