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