Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
va trien » va truyen, va thiet, va tuyen
hieu ve » hieu va, hieu van
xuc van » duc van, vuc van, xuc ban
luc van » luoc van, luu van, duc van
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai
vu va » vu van, tu va, su va
dich » dinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach y nang ((x hoi) or (o hoi)). hieu ve cam ((xuc van) OR (luc van)) dich vu va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach y nang ((x hoi) OR (o hoi)). hieu ve cam ((xuc van) OR (luc van)) dich vu va trien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach y nang ((x hoi) or (o hoi)). hieu ve cam ((xuc van) OR (luc van)) dich vu va trien".
• Adding a wildcard symbol may retrieve word variants: thuoc sach y nang ((x hoi) or (o hoi)). hieu ve cam ((xuc van) OR (luc van)) dich vu va trien*.