stringa='<a href="http://www.knovel.com.ezproxy.auckland.ac.nz/knovel2/databook/pdf/1424/70539_';
stringb='">text</a><br><br>';

myString='';

for i=1:25
    if i<= 9
        numstring=['0' num2str(i)];
    else
        numstring=num2str(i);
    end
            
    for j=0:16
        switch j
            case 0
                currentstring=[numstring '.pdf'];
            case 1
                currentstring=[numstring 'a.pdf'];
            case 2
                currentstring=[numstring 'b.pdf'];
             case 3
                currentstring=[numstring 'c.pdf'];
             case 4
                currentstring=[numstring 'd.pdf'];
             case 5
                currentstring=[numstring 'e.pdf'];                
             case 6
                currentstring=[numstring 'f.pdf'];
             case 7
                currentstring=[numstring 'g.pdf'];
             case 8
                currentstring=[numstring 'h.pdf'];
             case 9
                currentstring=[numstring 'i.pdf'];                
             case 10
                currentstring=[numstring 'j.pdf'];
             case 11
                currentstring=[numstring 'k.pdf'];
             case 12
                currentstring=[numstring 'l.pdf'];
             case 13
                currentstring=[numstring 'm.pdf'];                
             case 14
                currentstring=[numstring 'n.pdf'];                
             case 15
                currentstring=[numstring 'o.pdf'];
             case 16
                currentstring=[numstring 'p.pdf'];
        end
        myString=[myString [stringa currentstring stringb]];
    end
end