Perhaps you should try some spelling variations:
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
sach ky » sac ky, sach y, sach ty
hai van » thai van, ha van, hai tan
su sach » so sach, vu sach
hieu he » hieu ve, hiem he, hieu le
nang xa » lang xa, nang ma, mang xa
hai va » thai va, hoi va, mai va
he am » he nam, ve am

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