Is this the right way to make a dtd?

Question

if i have an xml file like this:

<books>
    <book>

        <title></title>
        <subtitle></subtitle>
        <info language="">

            <pages></pages>
            <chapters></chapters>

        </info>

        <author></author>

    </book>
    .
    .
    .
</books>

which one of this is the right dtd? FIRST WAY

    <!ELEMENT books(book+)>
    <!ELEMENT book(title,subtitle,info,author)>
    <!ELEMENT title (#PCDATA)>
    <!ELEMENT subtitle (#PCDATA)>
    <!ELEMENT info(pages,chapters)>
    <!ELEMENT pages (#PCDATA)>
    <!ELEMENT chapters(#PCDATA)>
    <!ELEMENT author(#PCDATA)>
    <!ATTLIST info language CDATA #REQUIRED>

SECOND WAY

   <!ELEMENT books(book+)>
   <!ELEMENT book(title,subtitle,info,author)>
   <!ELEMENT info(pages,chapters)>
   <!ELEMENT title (#PCDATA)>
   <!ELEMENT subtitle (#PCDATA)>
   <!ELEMENT pages (#PCDATA)>
   <!ELEMENT chapters(#PCDATA)>
   <!ELEMENT author(#PCDATA)>
   <!ATTLIST info language CDATA #REQUIRED>

So my questions are:

1. If i have a nested node do i write it at the start or as soon is encounter it?
2. Can i write attributes at the bottom or as soon is encounter it?

thanx if anyone will reply and sorry for my english.

Answer 1

Both cases do work after you add some spaces:
The first one can be:

<!DOCTYPE stylesheet [
    <!ELEMENT books (book+)>
    <!ELEMENT book (title,subtitle,info,author)>
    <!ELEMENT title (#PCDATA)>
    <!ELEMENT subtitle (#PCDATA)>
    <!ELEMENT info (pages,chapters)>
    <!ELEMENT pages (#PCDATA)>
    <!ELEMENT chapters (#PCDATA)>
    <!ELEMENT author (#PCDATA)>
    <!ATTLIST info language CDATA #REQUIRED>
]>
<books>
    <book>
        <title></title>
        <subtitle></subtitle>
        <info language="">
            <pages></pages>
            <chapters></chapters>
        </info>
        <author></author>
    </book>
    .
    .
    .
</books>

And the second one can be:

<!DOCTYPE stylesheet [
   <!ELEMENT books (book+)>
   <!ELEMENT book (title,subtitle,info,author)>
   <!ELEMENT info (pages,chapters)>
   <!ELEMENT title (#PCDATA)>
   <!ELEMENT subtitle (#PCDATA)>
   <!ELEMENT pages (#PCDATA)>
   <!ELEMENT chapters (#PCDATA)>
   <!ELEMENT author (#PCDATA)>
   <!ATTLIST info language CDATA #REQUIRED>
]>
<books>
    <book>
        <title></title>
        <subtitle></subtitle>
        <info language="">
            <pages></pages>
            <chapters></chapters>
        </info>
        <author></author>
    </book>
    .
    .
    .
</books>

In both cases you have to add a space after the element's name.
The result is the same in both cases.
That's the whole thing you need to fix/change.