Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cam thuc » am thuc, nam thuc, cam thu
hieu ve » hieu va, hieu van
hang di » hang doi, hang vi, hang dien
va hang » van hang, va nang, va lang
thuc va » thuc vat, thuc dan, thuc day
nang xa » nang x, lang xa, nang ma
so sanh » do sanh
cuu tre » cua tre, cau tren, cau treo
ve cam » ve cham, ve cac, va cam
di cuu » di cau, di cua, dinh cuu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((((te sach) OR (toc sach))) or (so sanh)) ky nang xa hoi. hieu ve cam thuc va hang di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((te sach) OR (toc sach))) OR (so sanh)) ky nang xa hoi. hieu ve cam thuc va hang di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((te sach) OR (toc sach))) or (so sanh)) ky nang xa hoi. hieu ve cam thuc va hang di cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((((te sach) OR (toc sach))) or (so sanh)) ky nang xa hoi. hieu ve cam thuc va hang di cuu tre*.