Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
ky dang » ky nang, ky danh
nam tuc » nam thuc, nam truc, nam tu
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, tri cua
y dang » 2 dang, _ dang, b dang
tuc va » thuc va, truc va, tuc xa
cua te » cua tu

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 ((y dang) OR (ky dang)) xa hoi. hieu van nam tuc va hanh tai cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((y dang) OR (ky dang)) xa hoi. hieu van nam tuc va hanh tai cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach ((y dang) OR (ky dang)) xa hoi. hieu van nam tuc va hanh tai cua te*.