Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
sach ty » sach tu, sach thu, xach tay
lang xa » lang ha, dang xay, lang van
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
di cua » doi cua, de cua, do cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc ((sach ty) OR (sach y)) lang xa hoi. hieu van pham thuc va danh ((di cua) OR (dai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc ((sach ty) OR (sach y)) lang xa hoi. hieu van pham thuc va danh ((di cua) or (dai cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: thuoc ((sach ty) OR (sach y)) lang xa hoi. hieu van pham thuc va danh ((di cua) or (dai cua)) tre*.