In the extended, combined kana characters such as gyu, kyu, pyu, kya, etc, is the smaller kana symbol written after the larger kana symbol? And are there any variations in the writing rules between hiragana and katakana for those characters? It makes sense that it would be, but I'm just confirming so that I don't develop a poor writing habit, and I've looked a lot of places for this information but couldn't find it. Any info is appreciated.