For my thesis I would like to find integers (lying in a certain residue class) in small intervals which have large prime divisors. And for some reason I decided that I want all bounds appearing in my thesis to be explicit, so I am looking for something like the following result:


Given a residue class $a \pmod{m}$ and an integer $x \ge c_0$ (where $c_0 = c_0(m)$ may depend on $m$, but is bounded above by some explicit function of $m$), there exists an integer $n \equiv a \pmod{m}$ in the interval $[x, x + x^{c_1}]$ having a prime divisor larger than $n^{c_2}$.

Now, I don't really care about the constants $c_1$ and $c_2$, as long as $c_2 > c_1$. 

The theorem in [this][1] paper by Ramachandra is more or less what I need, except for the restriction on the residue class and the fact that it's not explicit. On the other hand, theorem 1 in [this][2] paper by Laishram and Shorey gives the above with $n^{c_2}$ replaced by $\frac{2}{m}x^{c_1}$ for $m \ge 3$, $x \ge 19$.


Does anyone have a reference (or proof) for me?

Full disclosure: I asked this question [here][3] two weeks ago, without much success, so I decided to try my luck here.


  [1]: http://jlms.oxfordjournals.org/content/s2-1/1/303.full.pdf
  [2]: http://www.isid.ac.in/~shanta/PAPERS/IndagLPAP.pdf
  [3]: http://math.stackexchange.com/questions/1992900/large-prime-divisors-in-small-intervals