Hi all, I'm currently applying for PhD/CDT positions, and I have one reference who is a great Professor who like has his own significant theorem and let's me know when they've come and tells me to pester him to send them. The other is an Professor in America (I'm in the UK) whose obscenely recognised in his field and a reference from him would be quite useful, and he said he would do it, but I haven't heard anything back from him, despite the number of emails I have sent him just to confirm that he received it or anything. I know he must be busy, but its been a while since he has last replied and I'm starting to worry that I won't hear back from my postgrad choices until ages away and I kind of want to know as soon as possible so I can start arranging things and making decisions, which I am incredibly bad at and take ages on. Should I ring up the unis I have applied to and get them to change the reference to, say my current Master's supervisor who will promptly send one? or should I keep emailing the Professor abroad? or should I just wait. I feel like I might end up with no offers simply because he can't be bothered to let me know or at least send them. Cheers.