Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tham tuc » tham thuc, nham thuc, pham thuc
thai tuc » thai thuc, thai thuy, thai hoc
dinh dai » dinh dat, sinh dai, dinh dao
ty nang » ky nang, ty hang, ly nang
xa dinh » xac dinh, va dinh, ba dinh
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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 nang) OR (ty xang)) ma hoi. lieu va ((tham tuc) or (thai tuc)) xa dinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty nang) OR (ty xang)) ma hoi. lieu va ((tham tuc) OR (thai tuc)) xa dinh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ty nang) OR (ty xang)) ma hoi. lieu va ((tham tuc) or (thai tuc)) xa dinh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty nang) OR (ty xang)) ma hoi. lieu va ((tham tuc) or (thai tuc)) xa dinh dai cua tre*.