Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
doc sach » hoc sach, toc sach, nuoc sach
te sach » toc sach
hang vi » hang va, hanh vi, hang di
va hang » van hang, va nang, va lang
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ty lang » tay lang, ty xang, ty hang
vi cua » vai cua, di cua
cua te » cua tu

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 (doc sach)) ty lang xa hoi. hieu va ((pham duc) OR (tham thuc)) va hang vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (doc sach)) ty lang xa hoi. hieu va ((pham duc) OR (tham thuc)) va hang vi cua te".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (doc sach)) ty lang xa hoi. hieu va ((pham duc) OR (tham thuc)) va hang vi cua te*.