Перейдите прямо к симплексмеру без xpath php

Еще очень новичок в php … У меня есть большая simplexmlstring, и я хочу получить все последние имена из файла и в какой статье они где:

что-то вроде:

номер статьи 0 должность автора 0 'van Tricht'
номер статьи 0 должность автора 1 'Nieman'
номер статьи 0 авторская позиция 2 'van Tricht'
номер статьи 0 должность автора 3 'Bour'
…..
статья номер 1 авторская позиция 0 'van Tricht'
статья номер 1 должность автора 1 «Неман»
статья номер 1 авторская позиция 2 'van Tricht'
статья номер 1 авторская позиция 3 'Bour'

Я хочу перейти непосредственно к Author->LastName но без использования xpath, я попробовал его с xpath, но тогда мои петли foreach дают странные результаты … это то, что я пробовал:

 <?php $i = 0; $j = 0; foreach ($xml->xpath('//AuthorList') as $AuthorList) { $i ++; $j = 0; foreach ($xml->xpath('//Author') as $Author) { $j ++; echo $i . "articlenumber " . "author position" . $AuthorList->Author->LastName; } } ?> не <?php $i = 0; $j = 0; foreach ($xml->xpath('//AuthorList') as $AuthorList) { $i ++; $j = 0; foreach ($xml->xpath('//Author') as $Author) { $j ++; echo $i . "articlenumber " . "author position" . $AuthorList->Author->LastName; } } ?> 

Это строка xml:

 SimpleXMLElement Object ( [PubmedArticle] => Array ( [0] => SimpleXMLElement Object ( [MedlineCitation] => SimpleXMLElement Object ( [@attributes] => Array ( [Owner] => NLM [Status] => In-Process ) [PMID] => 20538400 [DateCreated] => SimpleXMLElement Object ( [Year] => 2010 [Month] => 07 [Day] => 08 ) [Article] => SimpleXMLElement Object ( [@attributes] => Array ( [PubModel] => Print-Electronic ) [Journal] => SimpleXMLElement Object ( [ISSN] => 1090-2147 [JournalIssue] => SimpleXMLElement Object ( [@attributes] => Array ( [CitedMedium] => Internet ) [Volume] => 73 [Issue] => 3 [PubDate] => SimpleXMLElement Object ( [Year] => 2010 [Month] => Aug ) ) [Title] => Brain and cognition [ISOAbbreviation] => Brain Cogn ) [ArticleTitle] => Increased saccadic rate during smooth pursuit eye movements in patients at Ultra High Risk for developing a psychosis. [Pagination] => SimpleXMLElement Object ( [MedlinePgn] => 215-21 ) [Abstract] => SimpleXMLElement Object ( [AbstractText] => Abnormalities in eye tracking are consistently observed in schizophrenia patients and their relatives and have been proposed as an endophenotype of the disease. The aim of this study was to investigate the performance of patients at Ultra High Risk (UHR) for developing psychosis on a task of smooth pursuit eye movement (SPEM). Forty-six UHR patients and twenty-eight age and education matched controls were assessed with a task of SPEM and psychiatric questionnaires. Our results showed that both the corrective and non-corrective saccadic rates during pursuit were higher in the UHR group. There were however no differences in smooth pursuit gain between the two groups. The saccadic rate was related to positive UHR symptoms. Our findings indicate that abnormalities in SPEM are already present in UHR patients, prior to a first psychotic episode. These abnormalities occur only in the saccadic system. [CopyrightInformation] => 2010 Elsevier Inc. All rights reserved. ) [Affiliation] => Department of Psychiatry, Academic Medical Center, University of Amsterdam, The Netherlands. mjvantricht@amc.uva.nl [AuthorList] => SimpleXMLElement Object ( [@attributes] => Array ( [CompleteYN] => Y ) [Author] => Array ( [0] => SimpleXMLElement Object ( [@attributes] => Array ( [ValidYN] => Y ) [LastName] => van Tricht [ForeName] => MJ [Initials] => MJ ) [1] => SimpleXMLElement Object ( [@attributes] => Array ( [ValidYN] => Y ) [LastName] => Nieman [ForeName] => DH [Initials] => DH ) [2] => SimpleXMLElement Object ( [@attributes] => Array ( [ValidYN] => Y ) [LastName] => Bour [ForeName] => LJ [Initials] => LJ ) [3] => SimpleXMLElement Object ( [@attributes] => Array ( [ValidYN] => Y ) [LastName] => Boerée [ForeName] => T [Initials] => T ) [4] => SimpleXMLElement Object ( [@attributes] => Array ( [ValidYN] => Y ) [LastName] => Koelman [ForeName] => JHTM [Initials] => JH ) [5] => SimpleXMLElement Object ( [@attributes] => Array ( [ValidYN] => Y ) [LastName] => de Haan [ForeName] => L [Initials] => L ) [6] => SimpleXMLElement Object ( [@attributes] => Array ( [ValidYN] => Y ) [LastName] => Linszen [ForeName] => DH [Initials] => DH ) ) ) [Language] => eng 

и т.д…………