Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cau tren » dau tren, ca tren, cau treo
thanh do » thanh de, thanh pho, thanh hoa
tuc gia » tac gia, duc gia, toc gia
cau tuc » cau truc, cau tu, cau luc
hieu ve » hieu va, hieu van
van hoi » van hoa, van hoc, van hoe
yu hang » yu zhang, yu pang, yu wang
ty hang » ly hang, ty xang, thi hang
cu tren » tu tren, dua tren
ve cau » ke cau, va cau, ve cac

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 ((ty hang) or (yu hang)) van hoi. hieu ve cau tuc gia thanh do ((cau tren) OR (cu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty hang) OR (yu hang)) van hoi. hieu ve cau tuc gia thanh do ((cau tren) OR (cu tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ty hang) or (yu hang)) van hoi. hieu ve cau tuc gia thanh do ((cau tren) OR (cu tren))".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty hang) or (yu hang)) van hoi. hieu ve cau tuc gia thanh do ((cau tren) OR (cu tren))*.