Perhaps you should try some spelling variations:
cham hoc » cham soc, chat hoc, cham hoi
thanh di » thanh doi, thanh de, thanh do
cau tren » cu tren, dau tren, ca tren
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
hoc gia » hoc giao, hoc giai, toc gia
di cau » da cau, diem cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang xa hoi. ((hieu ve) or (lieu va)) cham hoc gia thanh di cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang xa hoi. ((hieu ve) OR (lieu va)) cham hoc gia thanh di cau tren.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang xa hoi. ((hieu ve) or (lieu va)) cham hoc gia thanh di cau tren*.