'undertake greater efforts' is a correct and usable phrase in written English.
You can use this phrase when you need to emphasize the need to persist in a difficult situation or when you want to encourage someone to do more than what they have been doing. For example, you can say "We need to undertake greater efforts if we are going to succeed in this project".
"Labour and the hours that follow are the highest risk period for women and babies, and many women and their families undertake great efforts to reach health facilities to give birth, travelling long distances at expense.
"There are only hard choices left," said Rehn. "We are undertaking great efforts.
Facing what he has called the worst crisis for Cyprus since the 1974 Turkish invasion, Mr. Anastasiades said on Saturday on his Twitter account: "We are undertaking great efforts.
During recent decades, the Indonesian government has undertaken great efforts to exploit the underground water resources through application of conventional technological solutions so far without lasting success.
Though we have undertaken great effort to replicate the in planta experiments reported here using wild-type I-CreI, we have been unable to obtain Arabidopsis transformants with the wild-type endonuclease gene, perhaps due to leaky expression of the endonuclease resulting in toxicity.
Rouviere (2016) explores the relationship between US and UK food firms' size and their level of prevention efforts and shows that when cross-contamination between units is unlikely, small firms undertake greater prevention efforts than large firms.
Having trained the soldiers to fight, it is now undertaking its greatest effort ever to ease their return to "civilian" life.
Given the study's findings that patients with acute lung injury often did not receive lung protective ventilation, greater efforts to implement lung protective ventilation in routine clinical practice should be undertaken to reduce patients' long term mortality.
Let's make greater efforts".
And on the fact that, in Nigeria, the disease is continuing to spread despite great efforts undertaken by the government.
Consequently, why bipedalism, hairlessness, and the human family originated persist as puzzling questions despite the great efforts undertaken to explain them.
