https://marketor.ir/marketing/%d8%a8%d8%a7%d8%b2%d8%a7%d8%b1-%db%8c%d8%a7%d8%a8%db%8c-%d8%a7%db%8c%d9%86%d8%aa%d8%b1%d9%86%d8%aa%db%8c/identify-the-customer-and-target-market-in-niche-marketing/