Additional GMAT practice questions can be found in a variety of sources, which can help test-takers further prepare for the exam. These sources provide a range of question types and difficulty levels, allowing individuals to enhance their skills and familiarize themselves with the test format. Here are a few sources that offer additional GMAT practice questions:

1. Official GMAT Prep Software:
The Official GMAT Prep Software, developed by the Graduate Management Admission Council (GMAC), provides access to real GMAT questions. This software offers two free practice exams and additional question packs that can be purchased. It is considered one of the most reliable sources for GMAT practice questions.

2. GMAT Prep Books:
Numerous GMAT prep books are available in both print and digital formats. These books include practice questions, explanations, and strategies to tackle different question types. Some popular GMAT prep books include "The Official Guide for GMAT Review" and "Manhattan Prep GMAT Strategy Guides."

3. Online Forums and Communities:
Joining online forums and communities dedicated to GMAT preparation can provide access to a wide range of practice questions. Websites like EduRev allow users to discuss and share questions, providing an opportunity to solve new problems and learn from others' approaches.

4. GMAT Coaching Institutes:
Many coaching institutes offer GMAT preparation courses that include practice questions. These institutes provide study materials, mock tests, and question banks to help students practice effectively.

5. GMAT Mobile Apps:
Several mobile apps are available that offer GMAT practice questions. These apps allow users to solve questions on the go and track their progress. Some popular GMAT apps include "GMAT Club Math and Verbal" and "Magoosh GMAT Prep."

It is important to note that while these sources provide additional practice questions, it is also crucial to focus on understanding the concepts and strategies behind each question. Simply solving questions without analyzing the answers and learning from mistakes may not be as effective. Therefore, it is recommended to combine practice questions with thorough study materials and expert guidance to achieve the best results in the GMAT exam.