<!ELEMENT tema (studenti,(specializare)+)>
<!ELEMENT studenti (student)+>
<!ELEMENT student (nume,prenume,varsta,grupa,an)>
<!ELEMENT nume (#PCDATA)>
<!ELEMENT prenume (#PCDATA)>
<!ELEMENT varsta (#PCDATA)>
<!ELEMENT grupa (#PCDATA)>
<!ELEMENT an (#PCDATA)>
<!ELEMENT specializare (#PCDATA)>
<!ATTLIST student id_student CDATA #REQUIRED>
<!ATTLIST specializare id_student CDATA #REQUIRED>