Landing speed of Airbus 320:
GW minus 30 = vls
example: GW = 58000: 58 - 30 = 28 from that: 128 is vls
no wind: vls + 5 = 133 is approach speed
if wind: 133 + 1/3 of headwind component = approach speed corrected for headwind (ground speed mini) to keep minimum ground speed
The GW calculation is my own rule of thumb, but if you check the manuals it is working perfectly allright, it is just little bit conservative at high weights