Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
van cai » van hai, van chi, van cau
cai tao » cau tao, tai tao, ai tao
va hanh » van hanh, va thanh, va danh
x hoi » xa hoi, o hoi, x ho

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 ((ty nang) or (ty hang)) x hoi. hieu van cai tao va hanh ((vi luu) or (vi lua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty nang) OR (ty hang)) x hoi. hieu van cai tao va hanh ((vi luu) OR (vi lua)) tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty nang) or (ty hang)) x hoi. hieu van cai tao va hanh ((vi luu) or (vi lua)) tre*.