Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
thanh ve » hanh ve, thanh va, thanh vien
doc sach » hoc sach, nuoc sach, dac sac
luoc gia » quoc gia, luc gia, luong gia
cam luoc » cam xuc, tom luoc, cam lo
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
ve cuu » ve cau, ve chu, ve cua

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)) ty nang xa hoi. ((hieu ve) or (hieu va)) cam luoc gia thanh ve cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ty nang xa hoi. ((hieu ve) OR (hieu va)) cam luoc gia thanh ve cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ty nang xa hoi. ((hieu ve) or (hieu va)) cam luoc gia thanh ve cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ty nang xa hoi. ((hieu ve) or (hieu va)) cam luoc gia thanh ve cuu tre*.