Perhaps you should try some spelling variations:
hang truc » khung truc
dua tren » dung tren
hieu van » hieu va, thien van, lieu va
doanh vi » doanh va, doan vi, doanh vien
va doanh » van doanh, vay doanh, va danh
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
ha truc » ba truc, ha thuc, cau truc
nang xa » nang x, lang xa, nang ma
cuu tre » cua tre, cau tren, cau treo

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang xa hoi. hieu van ((ha truc) OR (hang truc)) va doanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. hieu van ((ha truc) OR (hang truc)) va doanh vi ((dua tren) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. hieu van ((ha truc) OR (hang truc)) va doanh vi ((dua tren) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. hieu van ((ha truc) OR (hang truc)) va doanh vi ((dua tren) or (cuu tre))*.