Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
lang xa » lang ha, dang xay, lang van
ty lang » tay lang, ty xang, ty hang
cuu tre » cua tre, cau tren, cau treo
va nam » van nam, ha nam
va nay » va ngay, va cay
di cuu » di cau, di cua, dinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) ty lang xa hoi. hieu ((va nam) or (va nay)) tu va hanh di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty lang xa hoi. hieu ((va nam) OR (va nay)) tu va hanh di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ty lang xa hoi. hieu ((va nam) or (va nay)) tu va hanh di cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ty lang xa hoi. hieu ((va nam) or (va nay)) tu va hanh di cuu tre*.