Perhaps you should try some spelling variations:
truc ngan » tu ngan, thu ngan, tri ngan
ca tren » cau tren, cu tren, co tren
hang di » hang doi, hang vi, hang dien
qua cau » quan cau, qua cac, qua ca
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty xang, ly nang
ty hang » ly hang, ty xang, thi hang
la tren » loai tren, dua tren, dat tren
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: tu sach ((ty nang) or (ty hang)) x hoi. hieu qua cau truc ngan hang di ((ca tren) or (la tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty hang)) x hoi. hieu qua cau truc ngan hang di ((ca tren) OR (la tren)).
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty hang)) x hoi. hieu qua cau truc ngan hang di ((ca tren) or (la tren))*.