Ignore paid ads at the top, whatever the firm search results are at the top of the page you want – they are very good in SEO or will not be so much in their website as a natural list!
To make things a little brief, you can try to expand your search. Say you live in Singapore and want a local agency – just type “SEO Agencies “. Or if your website is specific and you want special assistance with it, you can add your industry or site type – “SEO Tourism” or “SEO Buildings” for example. It’s a great way to find these specialized SEO agencies that have expert expertise in your area.