If its Yellow suckling clover (lesser trefoil) you can use Verdone Extra, but if its Oxalis corniculata, it won't work, info from the RHS re this weed in lawns

https://www.rhs.org.uk/advice/profile?PID=498

That's a new name for Lesser Trefoil, Bamboo, haven't heard that one before.
The plant could also be Black Medick, which I've found to be quite resistant to weedkillers.

In my experience, Black Medick can be killed by selective weed killers, IF you mix it with a wetting agent.

I wish I had more clover in my lawn

Verdone extra deals with black medic in lawns - just not oxalis.