Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va triet » va thiet, va trien, ve triet
sach ty » sach y, sach tu, sach thu
ty lang » tay lang, ty xang, ty hang
lang xa » lang ha, dang xay, lang van
qua nam » quan nam, cua nam, quang nam
thu vat » thuc vat, thu va, thuat vat
danh di » danh du, xanh di, danh dien
hanh de » hanh ve, hanh kem

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 ty lang xa hoi. hieu qua nam thu vat ((danh di) or (hanh de)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty lang xa hoi. hieu qua nam thu vat ((danh di) OR (hanh de)) va triet.
• Adding a wildcard symbol may retrieve word variants: toc sach ty lang xa hoi. hieu qua nam thu vat ((danh di) or (hanh de)) va triet*.