Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
tham tuc » tham thuc, thai tuc, nham thuc
doc sach » hoc sach, nuoc sach, dac sac
dinh dao » dinh dat, minh dao, dinh cao
dinh dai » dinh dat, sinh dai, dinh tai
hang mai » hoang mai, hang tai, hang hai
va tham » van tham, va cham, va thanh
mai hoi » mai khoi, dai hoi, lai hoi
ty hang » ly hang, ty xang, thi hang
cua tre » cua te, cuu tre, cua triet
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 (doc sach)) ty hang mai hoi. lieu va tham tuc va ((dinh dai) OR (dinh dao)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ty hang mai hoi. lieu va tham tuc va ((dinh dai) OR (dinh dao)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (doc sach)) ty hang mai hoi. lieu va tham tuc va ((dinh dai) OR (dinh dao)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ty hang mai hoi. lieu va tham tuc va ((dinh dai) OR (dinh dao)) cua tre*.