I mixed 5ml H202 with 5ml KI with 5ml H2SO4 wit Na2So2O3 with 50ml. Now I am trying to figure out all the elementary steps for this reaction. A starch was added in this mixture to measure the reaction time with the thiosulfate and the I2. I was just wonder if anyone could give me all the elementary steps for this reaction?

I came up with this but it is wrong or incomplete.

H2O2+2I^-+2H^+ ---> I2 + 2H20
I2+I^- ----> I3^-
I2+2S2O3^2- ---> 2I^- + S4O6^-2
STARCH + I2 ---- BLUE

Now what steps am I missing exactly?
Any help would be appreciated.