Perhaps you should try some spelling variations:
thi nang » ki nang, thi hanh
gia hanh » gia thanh, giao hanh, gia anh
thi cong » tai cong, thien cong
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
du gia » duc gia, dau gia, vu gia
ve cau » va cau, le cau, ve cai
ke cau » ket cau
ve cac » va cac, vien cac

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 ((thi nang) or (thi cong)) xa hoi. hieu ve cac du gia hanh ((ve cau) OR (ke cau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((thi nang) OR (thi cong)) xa hoi. hieu ve cac du gia hanh ((ve cau) OR (ke cau)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((thi nang) or (thi cong)) xa hoi. hieu ve cac du gia hanh ((ve cau) OR (ke cau)) treo".
• Adding a wildcard symbol may retrieve word variants: su sach ((thi nang) or (thi cong)) xa hoi. hieu ve cac du gia hanh ((ve cau) OR (ke cau)) treo*.