1. I. Joó, On Riesz bases,Annales Univ. Sci. Budapest. Sect. Math.,31 (1988), 141–153.
2. I. Joó and M. Joó, On an arithmetical property of √2,Publ. Math. Debrecen.
3. I. Joó, On the distribution of the set $$\left\{ {\sum\limits_{i = 1}^n {\varepsilon _i q^i :\varepsilon _i \in \{ 0,1\} ,n \in N} } \right\}$$ ,Acta Math. Hung., 58 (1991).
4. P. Erdős, M. Joó and I. Joó, On a problem of Tamás Varga (to appear).
5. P. Erdős and I. Joó, On the expansions $$1 = \sum {q^{ - n_i } , 1< q< 2} $$ , 1