Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
nam thuc » nam thuoc, am thuc, nam thu
hai van » thai van, ha van, hai tan
sach ky » sac ky, sach y, sach kem
hieu le » hieu ve, hieu he, hieu ly
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
hai va » thai va, hoi va, mai va
le nam » ly nam, he nam, le na

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 ky) OR (sach ty)) nang xa hoi. hieu le nam thuc vat hanh ((hai va) or (hai van)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) nang xa hoi. hieu le nam thuc vat hanh ((hai va) OR (hai van)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach ty)) nang xa hoi. hieu le nam thuc vat hanh ((hai va) or (hai van)) triet*".