Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
toc sach » hoc sach, doc sach, thuoc sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
thi van » thi lan, thi hanh, thi nang
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet

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 ky nang xa hoi. ((thien van) or (thi van)) cham thuc va dinh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. ((thien van) OR (thi van)) cham thuc va dinh van cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. ((thien van) or (thi van)) cham thuc va dinh van cua tre*.