Perhaps you should try some spelling variations:
truc ngan » tu ngan, thu ngan, tri ngan
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
ty nang » ky nang, ty hang, ly nang
va cau » van cau, va cac, va dau
doi ca » doi cua, doi cay, duoi ca
x hoi » xa hoi, o hoi, x ho
di ca » di cau, di cua, li ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ty nang) or (ty xang)) x hoi. hieu va cau truc ngan hang ((di ca) OR (doi ca)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) x hoi. hieu va cau truc ngan hang ((di ca) OR (doi ca)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) or (ty xang)) x hoi. hieu va cau truc ngan hang ((di ca) OR (doi ca)) tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty xang)) x hoi. hieu va cau truc ngan hang ((di ca) OR (doi ca)) tren*.