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
doi cau » doi dau, di cau, doi ca
sach ty » sach y, sach tu, sach thu
so sach » so sanh, bo sach, co sach
ty nang » ky nang, ty xang, ty hang
va cam » va cham, va cao, va cai
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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 ((x hoi) or (o hoi)). hieu ((va cam) OR (va cac)) tuc xa truong doi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty nang ((x hoi) OR (o hoi)). hieu ((va cam) OR (va cac)) tuc xa truong doi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty nang ((x hoi) or (o hoi)). hieu ((va cam) OR (va cac)) tuc xa truong doi cau tren".
• Adding a wildcard symbol may retrieve word variants: so sach ty nang ((x hoi) or (o hoi)). hieu ((va cam) OR (va cac)) tuc xa truong doi cau tren*.