International audience; The National Library Ivan Vazov in Plovdiv is the second largest library in Bulgaria. It serves asthe second national legal depository of Bulgarian printed works. In addition, it has contributedsignificantly to the preservation and the digital ac...

We consider a (4+D)–dimensional Friedmann–Robertson–Walker type universe having complex scale factor R + iRI, where R is the scale factor corresponding to the usual 4–dimensional Universe while iRI is that of D–dimensional space. It is then...

Professionally edited open access online encyclopaedias enable a systemic and reliable orientation within the ever-increasing amount of data and information on the Internet. Providing access to scientifically verified information, they represent an important part of the...