Perhaps you should try some spelling variations:
thien van » thi van
so sach » so sanh, bo sach, co sach
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
cac tuc » cac toc, cac tu, cac tac
van cac » van hac, van cau, van bac
ho nang » thi nang, kha nang, cao nang
lo nang » ly nang, loai nang, cao nang
ca tren » cau tren, cu tren, la tren
tuc va » thuc va, truc va, tuc xa

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

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