I was married with my ex-wife for 18 years. Before we got married my ex-wife was pregnant. As it was a void one, I gave talaq and remarried her once again. Subsequently, we were living happily until we encountered some differences and again I gave talaq. Subsequently we remarried again and was stable for sometime. Finally in 2012 I gave talaq again. I want to remarry her. However we have had technically 3 talaqs; my question is whether it is possible to marry her without her marrying another person?
Short answer - consult a scholar, otherwise advice by lay people may affect your marriage!
In a nutshell, as you have given three talaqs, you are technically divorced. Its not possible to marry her without her marrying another person. This is the severeity to enable people to understand that their actions will be accountable.