Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » thien van, lieu va, hieu ve
hanh tai » thanh tai, hang tai, han tai
va hanh » van hanh, va thanh, va danh
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
tai cua » thai cua, tai cuc, tri cua
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
nam tuc » nam thuc, nam truc, nam thuoc
nam tu » nam thu, nam thuc
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 dang xa hoi. ((hieu van) or (hieu va)) ((nam tuc) OR (nam tu)) va hanh tai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xa hoi. ((hieu van) OR (hieu va)) ((nam tuc) OR (nam tu)) va hanh tai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xa hoi. ((hieu van) or (hieu va)) ((nam tuc) OR (nam tu)) va hanh tai cua tu".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xa hoi. ((hieu van) or (hieu va)) ((nam tuc) OR (nam tu)) va hanh tai cua tu*.