Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
va doanh » van doanh, vay doanh, va danh
doanh vi » doanh va, doan vi, doanh vien
dua tren » dung tren
cau tren » cu tren, dau tren, ca tren
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
ha truc » ba truc, ha thuc, hang truc
truc va » thuc va, thuc vat, trung va
y nang » ky nang, ly nang, v nang
van ha » van hoa, van chat, van hanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang xa hoi. hieu van ha truc va doanh vi ((dua tren) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang xa hoi. hieu van ha truc va doanh vi ((dua tren) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: so sach y nang xa hoi. hieu van ha truc va doanh vi ((dua tren) or (cau tren))*.