Least totients in arithmetic progressions    (with  M. Garaev)
The least common multiple of  a quadratics sequence 
Sidon sets in N^d
Maximal coefficients of squares of Newman Polynomials
Probabilistic constructions of B_2[g] sequences
On a question of Sarkozy on gaps of product sequences    (with Thai Hoang Le)
A sumset problem     (with M. Silva and C. Vinuesa)
Repunit Lehmer numbers     (with  F. Luca)
Dense sets of integers with prescribed representation function     (with M. Nathanson)
On multiplicative magic squares     (with  F. Luca)