Perhaps you should try some spelling variations:
hanh vinh » thanh vinh, khanh vinh, hanh tinh
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
vinh cuu » dinh cuu, sinh cua, dinh cu
ky danh » ky anh
ky dang » ky nang
van bac » van ban, van bao, van hac
dac tan » dac san, dai tan, dap tan
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: toc sach ((ky danh) or (ky dang)) xa hoi. hieu van bac ((dac tan) OR (duc tan)) hanh vinh cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky danh) OR (ky dang)) xa hoi. hieu van bac ((dac tan) OR (duc tan)) hanh vinh cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ky danh) or (ky dang)) xa hoi. hieu van bac ((dac tan) OR (duc tan)) hanh vinh cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky danh) or (ky dang)) xa hoi. hieu van bac ((dac tan) OR (duc tan)) hanh vinh cuu tre*.