Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu va » lieu va, hieu qua
thu vat » thuc vat, thu va, thuat vat
vat dan » va dan, van dan, vat ran
dan vai » dan va, dan tai, dan vat
vai cau » va cau, van cau, vai cac
va nam » van nam, ha nam, va nay

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 tang xa hoi. hieu va nam thu vat dan vai cau tao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky tang xa hoi. hieu va nam thu vat dan vai cau tao.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) ky tang xa hoi. hieu va nam thu vat dan vai cau tao*.