Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cau tren » dau tren, ca tren, cau treo
thanh di » thanh doi, thanh de, thanh do
va thanh » gia thanh, ban thanh, va tinh
cham tuc » nham thuc, pham thuc, tham thuc
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
nang co » nang cao, nang doc, nang noi
bo sach » co sach, hoc sach
cu tren » tu tren, dua tren
co hoi » co hoc, co loi
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (bo sach)) ky nang co hoi. hieu ve cham tuc va thanh di ((cau tren) OR (cu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (bo sach)) ky nang co hoi. hieu ve cham tuc va thanh di ((cau tren) OR (cu tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (bo sach)) ky nang co hoi. hieu ve cham tuc va thanh di ((cau tren) OR (cu tren))".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (bo sach)) ky nang co hoi. hieu ve cham tuc va thanh di ((cau tren) OR (cu tren))*.