Perhaps you should try some spelling variations:
truong doi » truong dai, trong doi, truong hoi
xa truong » cac truong
cau tren » cu tren, dau tren, ca tren
nam thuc » nam thuoc, am thuc, nam thu
cam tuc » cam xuc, cam tu, dam thuc
doi cau » doi dau, di cau, doi ca
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
ty nang » ky nang, ty hang, ly nang
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: so sach ((ty nang) or (ty xang)) x hoi. hieu va ((cam tuc) OR (nam thuc)) xa truong doi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ty nang) OR (ty xang)) x hoi. hieu va ((cam tuc) OR (nam thuc)) xa truong doi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ty nang) or (ty xang)) x hoi. hieu va ((cam tuc) OR (nam thuc)) xa truong doi cau tren".
• Adding a wildcard symbol may retrieve word variants: so sach ((ty nang) or (ty xang)) x hoi. hieu va ((cam tuc) OR (nam thuc)) xa truong doi cau tren*.