Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
nam tuc » nam thuc, nam truc, nam tu
tuc va » thuc va, truc va, tuc xa
cua tu » cua tuc, cua su, cua cu

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 lang) OR (ky dang)) xa hoi. hieu van nam tuc va thanh tai ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky lang) OR (ky dang)) xa hoi. hieu van nam tuc va thanh tai ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ky lang) OR (ky dang)) xa hoi. hieu van nam tuc va thanh tai ((cua te) or (cua tu))".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky lang) OR (ky dang)) xa hoi. hieu van nam tuc va thanh tai ((cua te) or (cua tu))*.