Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dua tren » dung tren
va thanh » ban thanh, va tinh, le thanh
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
cuu tre » cua tre, cau tren, cau treo
ma hoi » mai hoi, xa hoi, ma hoa

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 nang ma hoi. hieu ve pham duc ((va thanh) or (gia thanh)) lai ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang ma hoi. hieu ve pham duc ((va thanh) OR (gia thanh)) lai ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang ma hoi. hieu ve pham duc ((va thanh) or (gia thanh)) lai ((dua tren) or (cuu tre))*.