Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
toc sach » hoc sach, doc sach, thuoc sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vai su » va su, lai su, tai su
van su » dan su

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: toc sach ty nang ma hoa. hieu ve pham thuc va hanh ((vai su) OR (van su)) triet~.
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang ma hoa. hieu ve pham thuc va hanh ((vai su) or (van su)) triet*.