Perhaps you should try some spelling variations:
thien van » thi van
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
cau luc » cau truc, cau phuc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
lo nang » ho nang, ly nang, loai nang
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (thu sach)) lo nang xa hoi. ((thien van) or (hieu va)) cau luc va danh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) lo nang xa hoi. ((thien van) OR (hieu va)) cau luc va danh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) lo nang xa hoi. ((thien van) or (hieu va)) cau luc va danh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) lo nang xa hoi. ((thien van) or (hieu va)) cau luc va danh vi cua tre*.