Perhaps you should try some spelling variations:
thuat lanh » thuat lap, thuat san
trinh cuu » trinh cau, trinh cua, trinh chu
co sach » bo sach, cuon sach, hoc sach
hieu ve » hieu va, hieu van
va dinh » van dinh, va kinh, va tinh
tri cuu » tri cua, tra cuu, troi cua
ve dat » de dat, va dat, ve dao
x hoi » xa hoi, o hoi, x ho
nuoc » quoc, duoc, ngoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((co sach) or (thuat lanh)) ky nang x hoi. hieu ve dat nuoc va dinh ((tri cuu) OR (trinh cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((co sach) OR (thuat lanh)) ky nang x hoi. hieu ve dat nuoc va dinh ((tri cuu) OR (trinh cuu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((co sach) or (thuat lanh)) ky nang x hoi. hieu ve dat nuoc va dinh ((tri cuu) OR (trinh cuu)) tre".
• Adding a wildcard symbol may retrieve word variants: ((co sach) or (thuat lanh)) ky nang x hoi. hieu ve dat nuoc va dinh ((tri cuu) OR (trinh cuu)) tre*.