Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van cham » van chat, van tham, va cham
hieu van » hieu va, thien van, lieu va
cham tuc » nham thuc, pham thuc, tham thuc
ty nang » ty xang, ty hang, ly nang
va danh » va dan, va hanh, dia danh
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
di cua » dai cua, doi cua, de cua

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