Perhaps you should try some spelling variations:
nhanh thai » nhanh thi, nhanh thanh, nhanh thang
hoang hai » hoang thi, hoang van
hieu van » hieu va, thien van, lieu va
cau nuoc » cap nuoc, cac nuoc, dau nuoc
cau treo » cau theo, cau tren, cau triet
su sach » so sach, vu sach
van cau » van dau, van hau, van chat
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, 5 hoi

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 y nang ((x hoi) OR (x ho)). hieu van cau nuoc va ((nhanh thai) or (hoang hai)) cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((x hoi) OR (x ho)). hieu van cau nuoc va ((nhanh thai) OR (hoang hai)) cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((x hoi) OR (x ho)). hieu van cau nuoc va ((nhanh thai) or (hoang hai)) cau treo".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((x hoi) OR (x ho)). hieu van cau nuoc va ((nhanh thai) or (hoang hai)) cau treo*.