Perhaps you should try some spelling variations:
hang hai » hoang hai, thanh hai, hang va
hang tai » hang va, dung tai
te sach » toc sach
hieu ve » hieu va, hieu van
ve giao » te giao, viet giao, van giao
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, me hoi
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y nang ((ma hoi) or (ma hoa)). hieu ve giao duc va ((hang hai) OR (hang tai)) cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ((ma hoi) OR (ma hoa)). hieu ve giao duc va ((hang hai) OR (hang tai)) cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ((ma hoi) or (ma hoa)). hieu ve giao duc va ((hang hai) OR (hang tai)) cua su".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((ma hoi) or (ma hoa)). hieu ve giao duc va ((hang hai) OR (hang tai)) cua su*.