Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
sach van » sach han, sach va, bach van
van nang » van quang, van ban, van dong
vat hanh » vat thanh, van hanh, va hanh
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
vi cua » vai cua
di cua » dai cua, doi cua, de 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 van nang xa hoi. ((hieu va) OR (lieu va)) cham thuc vat hanh ((vi cua) or (di cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach van nang xa hoi. ((hieu va) OR (lieu va)) cham thuc vat hanh ((vi cua) OR (di cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach van nang xa hoi. ((hieu va) OR (lieu va)) cham thuc vat hanh ((vi cua) or (di cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach van nang xa hoi. ((hieu va) OR (lieu va)) cham thuc vat hanh ((vi cua) or (di cua)) tre*.