Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
dinh dau » dinh dat, dinh du, danh dau
van pham » san pham, van phan, van phat
dau cua » dai cua, day cua, cau cua
va dinh » van dinh, va kinh, va tinh
thuc va » thuc vat, thuc dan, thuc day
thi van » thi lan, thi hanh, thi nang
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach ty, sach kem
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc ((sach ky) or (sach y)) ((nang ma) OR (sang ma)) hoi. thi van pham thuc va dinh dau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc ((sach ky) OR (sach y)) ((nang ma) OR (sang ma)) hoi. thi van pham thuc va dinh dau cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc ((sach ky) or (sach y)) ((nang ma) OR (sang ma)) hoi. thi van pham thuc va dinh dau cua tre".
• Adding a wildcard symbol may retrieve word variants: thuoc ((sach ky) or (sach y)) ((nang ma) OR (sang ma)) hoi. thi van pham thuc va dinh dau cua tre*.