Different breathing patterns

[Time Traveler]

I've started holotropic  breath-work practice recently and become interested in other breathing exercises too.

Apart from yoga pranayamas I know some simple breathing patterns:

1) breath of relief (deeply breathe in and then freely let out all your stress)

2) four types of interval breathing with different lengths of each phase:

  a) breath in, breathe out, pause

  b) breath in, pause, breathe out,

  c) breath in, pause, breathe out, pause

Most of breath-work gurus advocate only one of these types, but I cannot find a description of how they are different and what effects is from each of them.

Maybe someone knows a resource where this is described ?