Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
van hanh » van thanh, ban hanh, van anh
toc sach » hoc sach, doc sach, thuoc sach
thuc van » thuc vat, thuc dan, thuc va
su sach » so sach, vu sach
ve pham » vi pham, v pham, ve phan
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
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: ((su sach) or (toc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu ve pham thuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu ve pham thuc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (toc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu ve pham thuc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (toc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu ve pham thuc van hanh vi cua tre*.