Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu quan » lieu quan, thien quan, lien quan
ban thanh » ban hanh, ban hang
thu sach » tu sach, thuoc sach, thu hoach
thanh di » thanh doi, thanh de, thanh do
duc ban » duc tan, duc van, dua ban
nang xa » nang x, lang xa, nang ma
dau duc » dao duc, dang duc, dau nuoc
di cua » dai cua, doi cua, de cua
y nang » ky nang, ly nang, v nang
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (thuat sach)) y nang xa hoi. ((hieu quan) or (hieu qua)) dau duc ban thanh di cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuat sach)) y nang xa hoi. ((hieu quan) OR (hieu qua)) dau duc ban thanh di cua tu.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuat sach)) y nang xa hoi. ((hieu quan) or (hieu qua)) dau duc ban thanh di cua tu*.