Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
dung hai » dung tai, dung ha, dung sai
dang hai » dang khai, hang hai, dong hai
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
y nang » ky nang, ly nang, v nang
ma hoi » xa hoi, ma hoa, me hoi
cua te » cua tu

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

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