Perhaps you should try some spelling variations:
van cham » van chat, van tham, va cham
cham hoc » cham soc, chat hoc, cham hoi
hieu van » hieu va, thien van, lieu va
hoc gia » hoc giao, hoc giai, toc gia
vu sach » vu bach, vu khach
nang xa » nang x, lang xa, nang ma
su sach » so sach
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.

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) OR (su sach)) ky nang xa hoi. hieu van cham hoc gia thanh ((vi su) or (ki su)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (su sach)) ky nang xa hoi. hieu van cham hoc gia thanh ((vi su) OR (ki su)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) OR (su sach)) ky nang xa hoi. hieu van cham hoc gia thanh ((vi su) or (ki su)) tren".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) OR (su sach)) ky nang xa hoi. hieu van cham hoc gia thanh ((vi su) or (ki su)) tren*.