Perhaps you should try some spelling variations:
phan thuc » nhan thuc, phap thuc, pham thuc
vat hanh » vat thanh, van hanh, va hanh
su sach » so sach, vu sach
ty hang » ly hang, thi hang, thu hang
hieu ve » hieu va, hieu van
ve phan » va phan, ke phan, ve phat
te cua » tue cua, de cua
le cua » ly cua

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 ((ty hang) OR (ty xang)) xa hoi. hieu ve phan thuc vat hanh ((te cua) or (le cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty hang) OR (ty xang)) xa hoi. hieu ve phan thuc vat hanh ((te cua) OR (le cua)) te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty hang) OR (ty xang)) xa hoi. hieu ve phan thuc vat hanh ((te cua) or (le cua)) te*".