Perhaps you should try some spelling variations:
thanh dat » thanh san, thanh hai, thanh van
va thanh » gia thanh, ban thanh, va tinh
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
ky dang » ky danh
ve chim » va chim, ve cham, ve chinh
va cham » va chat, va tham
thuc va » thuc vat, thuc dan, thuc day

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 ((ky dang) OR (ky nang)) xa hoi. hieu ((ve chim) or (va cham)) thuc va thanh dat va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky nang)) xa hoi. hieu ((ve chim) OR (va cham)) thuc va thanh dat va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) OR (ky nang)) xa hoi. hieu ((ve chim) or (va cham)) thuc va thanh dat va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) OR (ky nang)) xa hoi. hieu ((ve chim) or (va cham)) thuc va thanh dat va triet*.