Perhaps you should try some spelling variations:
dieu cua » dieu tra
vat hanh » vat thanh, van hanh, va hanh
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
nang co » nang cao, nang doc, nang noi
ve cac » va cac, vien cac
ve cam » ve cham, va cam, ve cai
co hoi » co hoc, co loi
de cua » le cua, te cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang co hoi. hieu ((ve cam) or (ve cac)) thuc vat hanh ((de cua) OR (dieu cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang co hoi. hieu ((ve cam) OR (ve cac)) thuc vat hanh ((de cua) OR (dieu cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang co hoi. hieu ((ve cam) or (ve cac)) thuc vat hanh ((de cua) OR (dieu cua)) triet".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang co hoi. hieu ((ve cam) or (ve cac)) thuc vat hanh ((de cua) OR (dieu cua)) triet*.