Hi guys, Not actually a mathematics question as such (sorry) but does anyone know where i can get my hands on a copy of Chen's paper "On the representation of a large even integer as the sum of a prime and the product of at most two primes". For the life of me all i can find is references to it rather than an actual pdf copy, or even any information about the journal it is from (Sci. Sinica 16 (1973) 157-176) ie reference given below. http://en.wikipedia.org/wiki/Goldbach's_conjecture#cite_note-13 I have access to science direct and springer link but none seem to have it :( Any ideas? Cheers -G EDIT: Ok so i found that its in Scientia Sinica Series A which springerlink has going back to 1997, i'm assuming if they don't have volumes further back they're not available electronically?