Perhaps you should try some spelling variations:
tham thuc » pham thuc, tam thuc, thai thuc
nham thuc » nhan thuc, nam thuc, nham thu
pham chuc » pham duc, pham huu, kham chua
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
cuu tre » cua tre, cau tren, cau treo
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
vi cuu » vi luu, vinh cuu
tu sai » tu bai, tu san, tu cai
sai ky » sac ky
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: tu sai ky sang ma hoi. hieu van ((tham thuc) or (((pham chuc) or (nham thuc)))) ban hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky sang ma hoi. hieu van ((tham thuc) OR (((pham chuc) OR (nham thuc)))) ban hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sai ky sang ma hoi. hieu van ((tham thuc) or (((pham chuc) or (nham thuc)))) ban hanh vi cuu tre*.