Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
toc sach » hoc sach, doc sach, thuoc sach
kho tang » cao tang
tang mai » tang ma, tang tai, lang mai
cua tre » cua te, cuu tre, cua triet
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
va nham » va cham, va tham, va nha
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu bach) or (toc sach)) kho tang mai hoi. hieu va nham thuc ((va hanh) or (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu bach) OR (toc sach)) kho tang mai hoi. hieu va nham thuc ((va hanh) OR (va danh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((vu bach) or (toc sach)) kho tang mai hoi. hieu va nham thuc ((va hanh) or (va danh)) vi cua tre*.