Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
toc sach » hoc sach, doc sach, thuoc sach
lang van » dang van, tang van, hoang van
cua viet » ca viet, hoa viet, cua vat
nang ma » tang ma, sang ma, nang cao
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (tu sach)) ky ((nang ma) or (lang van)) hoi. hieu ve pham thuc va danh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (tu sach)) ky ((nang ma) OR (lang van)) hoi. hieu ve pham thuc va danh vi cua viet.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (tu sach)) ky ((nang ma) or (lang van)) hoi. hieu ve pham thuc va danh vi cua viet*.