Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
dong tri » dong tai, dung tri, dong thi
cap nuoc » dat nuoc
cac nuoc » hoc nuoc, dat nuoc, cua nuoc
hieu van » hieu va, thien van, lieu va
mai hoi » mai khoi, dai hoi, lai hoi
sach ky » sac ky, sach y, sach ty
va dong » van dong, ha dong, xa dong
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 ky nang ((ma hoi) or (mai hoi)). hieu van ((cac nuoc) OR (cap nuoc)) va dong tri cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang ((ma hoi) OR (mai hoi)). hieu van ((cac nuoc) OR (cap nuoc)) va dong tri cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang ((ma hoi) or (mai hoi)). hieu van ((cac nuoc) OR (cap nuoc)) va dong tri cua te".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang ((ma hoi) or (mai hoi)). hieu van ((cac nuoc) OR (cap nuoc)) va dong tri cua te*.