selenium webdriver to find the anchor tag and click that

<div id="ContentPrimary">
<ul class="selectors modeSelectors">
    <li><a href="/content/l411846326l1213g/references/" title="">
        <span class="selector">References (27)</span></a></li>
    <li><a href="/content/l411846326l1213g/referrers/" title="">
        <span class="selector">Cited By (2)</span></a></li>
    <li><a href="/content/l411846326l1213g/export-citation/" title="">
        <span class="selector">Export Citation</span></a></li>
    <li><a href="/content/l411846326l1213g/about/" title="">
        <span class="selector">About</span></a></li>
</ul>

In this I need to find and click About link using Selenium api but I was unable to do it.

what I did is

wait.until(new ExpectedCondition<Boolean>() {
    public Boolean apply(WebDriver webDriver) {
        System.out.println("Searching ...");
        String s = driver.findElement(By.cssSelector("#ContentPrimary ul li[4] span.selector")).getText();
        System.out.println(s);
        if (Pattern.compile(Pattern.quote("About"), Pattern.CASE_INSENSITIVE).matcher(s).find()) {
            return true;
        } else {
            return false;
        }
    }
});
driver.findElement(By.linkText("About")).click();

but its not working

In my experience the Selenium API has many flaws in that way. They can mostly only be overcome by reformulating your selectors. For example you could try using a XPath selector to get your element:

driver.findElement(By.xpath("//a[contains(.,'About')]")).click();

Also, if you are trying to use the Internet Explorer it might help not to click the element, but instead to simulate pushing the Enter button. So assumung the Element is found, you could try this:

driver.findElement(By.linkText("About")).sendKeys(Keys.ENTER);