Designing a non-inverting buck-boost converter
Could you provide a good reference where I can find the equations or
the equations themselves

No because that's a shopping question mixed with a question that solicits opinions and both will attract question closure.
If you are designing a synchronous buck-boost converter (4 transistors) then presumably you know how to design a synchronous buck converter and you know how to design a synchronous boost converter as individual items. If you don't know how to do this then your question will probably also be closed on the basis that you need to focus.

The input range of the converter will be big like 8v-70v and I want to
regulate the voltage to say 12V

So, assuming that you are still reading, consider this: -

For \$V_{IN}\$ up to 12 volts, SW1 is on and SW3 is off. SW4 and SW2 act as a synchronous boost converter: -


You don't need further explanation of this do you. If you say yes then you have read too far.

For \$V_{IN}\$ above 12 volts, SW2 is on and SW4 is off. SW1 and SW3 act as a synchronous buck converter: -


You don't need further explanation of this do you. If you say yes then you have read too far.

Can I simulate the converter in simulink

Simulink can simulate this circuit as far as I know.