1. Rath, T.: Vital friends: The People You Can’t Afford to Live Without. The Gallup Press, Washington (2006)
2. Ellison, N.B., Steinfield, C., Lampe, C.: The benefits of Facebook “Friends:” social capital and college student’s use of online social network sites. J. Comput.-Mediat. Commun. 12(4), 1143–1168 (2007)
3. Murata, I., Suzuki, N.: A newspaper-based analysis of minors’ legal responsibility for mobile phone-induced crimes: with special reference to articles of online dating sites related crimes. Japan J. Educ. Technol. 32(4), 435–442 (2009)
4. Ishii, Y., Aburai, T., Takeyasu, K.: An analysis of user attitudes to SNS. OIU J. Int. Stud. 26(2), 1–21 (2013)
5. Nguyen, T.T., Nguyen, D.T., Iqbal, S.T., Ofek, E. : The known stranger: supporting conversations between strangers with personalized topic suggestions. In: Proceedings. of CHI, pp. 555–564 (2015)