Perhaps you should try some spelling variations:
hieu quan » hieu qua, lieu quan, thien quan
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
quan cau » quang cao, toan cau, quan ha
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
cau luc » cau truc, cau phuc
va hanh » van hanh, va thanh, va danh
luc va » duc va, tuc va, loc va
vi cuu » vinh cuu
vi luu » vi lua

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 (thu hoach)) ky dang xay hoi. hieu quan cau luc va hanh ((vi cuu) or (vi luu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (thu hoach)) ky dang xay hoi. hieu quan cau luc va hanh ((vi cuu) OR (vi luu)) tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (thu hoach)) ky dang xay hoi. hieu quan cau luc va hanh ((vi cuu) or (vi luu)) tre*.