Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
mang mai » mang may, lang mai, mang lai
cua viet » ca viet, cua vat, cua dieu
thuc dan » thuc hanh, hoc dan, thuc vat
dan hanh » dang hanh, dan khanh, dan thanh
hanh vai » hanh vi, hanh va, hanh tai
va tham » van tham, va cham, va thanh
ky mang » ky nang, ke mang, ky dang
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
tu sac » tu sach, tu san, tu bac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sac) or (tu cac)) ky mang mai hoi. hieu va tham thuc dan hanh vai ((cua viet) or (hoa viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu cac)) ky mang mai hoi. hieu va tham thuc dan hanh vai ((cua viet) OR (hoa viet)).
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu cac)) ky mang mai hoi. hieu va tham thuc dan hanh vai ((cua viet) or (hoa viet))*.