Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
van cuu » van cau, van chu, van cu
va tinh » may tinh
va dinh » van dinh, va kinh, vu dinh
nam xua » nam cua, nam mua, nam qua
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
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: ((te sach) OR (toc sach)) ky tang xa hoi. hieu van nam xua ((va dinh) or (va tinh)) van cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky tang xa hoi. hieu van nam xua ((va dinh) OR (va tinh)) van cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky tang xa hoi. hieu van nam xua ((va dinh) or (va tinh)) van cuu tre*".