Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
danh tai » doanh tai, dinh tai, hanh tai
trung va » truong va, trang va, trung ha
doc sach » hoc sach, nuoc sach, dac sac
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat
tai cua » thai cua, tai cuc, tri cua
va cam » va cham, va cac, va cao
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) or (doc sach)) ky nang xa hoi. hieu va cam ((truc va) OR (trung va)) danh tai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky nang xa hoi. hieu va cam ((truc va) OR (trung va)) danh tai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (doc sach)) ky nang xa hoi. hieu va cam ((truc va) OR (trung va)) danh tai cua tu".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky nang xa hoi. hieu va cam ((truc va) OR (trung va)) danh tai cua tu*.