Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
pham hoc » phap hoc, phau hoc, pham hoa
dan danh » van danh, han danh, ban danh
danh bat » doanh bat, anh bai, dinh ba
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
bat cua » ban cua, mat cua, bai 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) or (hoc sach)) ky lang xa hoi. hieu van pham hoc dan danh bat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky lang xa hoi. hieu van pham hoc dan danh bat cua tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) ky lang xa hoi. hieu van pham hoc dan danh bat cua tre*.