Perhaps you should try some spelling variations:
dong cua » dung cua, cong cua, huong cua
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
di cua » dai cua, doi cua, de 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 ty nang xa hoi. hieu ve ((cap nuoc) OR (dat nuoc)) va hanh ((di cua) or (dong cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang xa hoi. hieu ve ((cap nuoc) OR (dat nuoc)) va hanh ((di cua) OR (dong cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang xa hoi. hieu ve ((cap nuoc) OR (dat nuoc)) va hanh ((di cua) or (dong cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang xa hoi. hieu ve ((cap nuoc) OR (dat nuoc)) va hanh ((di cua) or (dong cua)) tre*.