Complex sentence: The 35th IPhO was held in Pohang, South Korea from July 15th to 23rd, 2004; the 36th was held from July 3rd to 12th, 2005, in Salamanca, Spain.
Split into simpler sentences: The 35th IPhO was held in Pohang, South Korea from July 15th to 23rd, 2004. The next IPhO, the 36th, will be held from July 3rd to 12th, 2005, in Salamanca, Spain.