Chỉ hiện thị ảnh đầu tiên cho blogger

<!-- Blogger có thumbnail nguồn blogspot -->
<b:if cond='data:post.isFirstPost == &quot;true&quot;'>
<b:if cond='data:post.thumbnailUrl'>
    <img expr:alt='data:post.title' expr:src='data:post.thumbnailUrl' height='72' width='72'/>
   <b:else/>
  <img expr:alt='data:post.title' height='72' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPqqhxLV8MB3ooXvix0yUbYOTh4kMUqAHbLXMSjzkAFjFVU7GbGXhY0lhsy1O40f56qyjyhh5qgo1TeQPFJKundLE7vPJuFmHntTVjuU0jUlrBc8oEt92nji_NjbqpCscxiIdvJiUyptfs/' width='72'/>
</b:if></b:if>

<!-- Blogger có thumbnail nguồn ngoài -->
<b:if cond='data:post.isFirstPost == &quot;true&quot;'>
<b:if cond='data:post.firstImageUrl'>
    <img expr:alt='data:post.title' expr:src='data:post.firstImageUrl' height='72' width='72'/>
   <b:else/>
  <img expr:alt='data:post.title' height='72' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPqqhxLV8MB3ooXvix0yUbYOTh4kMUqAHbLXMSjzkAFjFVU7GbGXhY0lhsy1O40f56qyjyhh5qgo1TeQPFJKundLE7vPJuFmHntTVjuU0jUlrBc8oEt92nji_NjbqpCscxiIdvJiUyptfs/' width='72'/>
</b:if></b:if>