Perhaps you should try some spelling variations:
tham thuc » pham thuc, tam thuc, thai thuc
nham thuc » nhan thuc, nam thuc, nham thu
van thanh » ban thanh, van tuan
thanh vai » thanh hai, thanh van, thanh tai
cua triet » cua viet, su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
vai cua » dai cua, hai cua, lai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky tang ma hoa. hieu van ((tham thuc) or (nham thuc)) van thanh vai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky tang ma hoa. hieu van ((tham thuc) OR (nham thuc)) van thanh vai cua triet.
• Adding a wildcard symbol may retrieve word variants: thu sach ky tang ma hoa. hieu van ((tham thuc) or (nham thuc)) van thanh vai cua triet*.