Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
sang tao » hang tai
thuc cay » thuc day, thuc can, thuc cao
cay vanh » cay lanh, cay xanh, cac van
vanh dai » van dai, vanh tai, lanh dao
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
va tham » van tham, va cham, va thanh
sach v » sach va, sach y, sach 2
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach v ((nang ma) or (sang tao)) hoi. lieu va tham thuc cay vanh dai cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v ((nang ma) OR (sang tao)) hoi. lieu va tham thuc cay vanh dai cua su.
• Adding a wildcard symbol may retrieve word variants: su sach v ((nang ma) or (sang tao)) hoi. lieu va tham thuc cay vanh dai cua su*.