Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
sach kem » hanh kem
dua tren » dung tren
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
va pham » van pham, va phat, va phap
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach kem) or (sach y)) lang xa hoi. hieu va pham thuc va hanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach kem) OR (sach y)) lang xa hoi. hieu va pham thuc va hanh vi ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach kem) or (sach y)) lang xa hoi. hieu va pham thuc va hanh vi ((dua tren) or (cuu tre))*.