Perhaps you should try some spelling variations:
thanh van » thanh toan, thanh phan, thanh nhan
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nam qua » nam quan, nam cua, nam mua
qua ban » cua ban, qua quan
cuu tre » cua tre, cau tren, cau treo

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 nang ((xa hoi) or (ma hoa)). hieu van nam qua ban ((thanh van) OR (thanh san)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((xa hoi) OR (ma hoa)). hieu van nam qua ban ((thanh van) OR (thanh san)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((xa hoi) or (ma hoa)). hieu van nam qua ban ((thanh van) OR (thanh san)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((xa hoi) or (ma hoa)). hieu van nam qua ban ((thanh van) OR (thanh san)) cuu tre*.